245 lines
6.4 KiB
Plaintext
245 lines
6.4 KiB
Plaintext
[[indices-analyze]]
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== Analyze
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Performs the analysis process on a text and return the tokens breakdown
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of the text.
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Can be used without specifying an index against one of the many built in
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analyzers:
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"analyzer" : "standard",
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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If text parameter is provided as array of strings, it is analyzed as a multi-valued field.
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"analyzer" : "standard",
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"text" : ["this is a test", "the second text"]
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}
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--------------------------------------------------
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// CONSOLE
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Or by building a custom transient analyzer out of tokenizers,
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token filters and char filters. Token filters can use the shorter 'filter'
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parameter name:
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"tokenizer" : "keyword",
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"filter" : ["lowercase"],
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"tokenizer" : "keyword",
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"filter" : ["lowercase"],
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"char_filter" : ["html_strip"],
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"text" : "this is a <b>test</b>"
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}
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--------------------------------------------------
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// CONSOLE
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deprecated[5.0.0, Use `filter`/`char_filter` instead of `filters`/`char_filters` and `token_filters` has been removed]
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Custom tokenizers, token filters, and character filters can be specified in the request body as follows:
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"tokenizer" : "whitespace",
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"filter" : ["lowercase", {"type": "stop", "stopwords": ["a", "is", "this"]}],
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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It can also run against a specific index:
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[source,js]
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--------------------------------------------------
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GET analyze_sample/_analyze
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{
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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// TEST[setup:analyze_sample]
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The above will run an analysis on the "this is a test" text, using the
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default index analyzer associated with the `analyze_sample` index. An `analyzer`
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can also be provided to use a different analyzer:
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[source,js]
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--------------------------------------------------
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GET analyze_sample/_analyze
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{
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"analyzer" : "whitespace",
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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// TEST[setup:analyze_sample]
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Also, the analyzer can be derived based on a field mapping, for example:
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[source,js]
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--------------------------------------------------
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GET analyze_sample/_analyze
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{
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"field" : "obj1.field1",
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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// TEST[setup:analyze_sample]
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Will cause the analysis to happen based on the analyzer configured in the
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mapping for `obj1.field1` (and if not, the default index analyzer).
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A `normalizer` can be provided for keyword field with normalizer associated with the `analyze_sample` index.
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[source,js]
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--------------------------------------------------
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GET analyze_sample/_analyze
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{
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"normalizer" : "my_normalizer",
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"text" : "BaR"
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}
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--------------------------------------------------
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// CONSOLE
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// TEST[setup:analyze_sample]
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Or by building a custom transient normalizer out of token filters and char filters.
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"filter" : ["lowercase"],
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"text" : "BaR"
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}
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--------------------------------------------------
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// CONSOLE
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=== Explain Analyze
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If you want to get more advanced details, set `explain` to `true` (defaults to `false`). It will output all token attributes for each token.
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You can filter token attributes you want to output by setting `attributes` option.
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NOTE: The format of the additional detail information is labelled as experimental in Lucene and it may change in the future.
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[source,js]
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--------------------------------------------------
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GET _analyze
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{
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"tokenizer" : "standard",
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"filter" : ["snowball"],
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"text" : "detailed output",
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"explain" : true,
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"attributes" : ["keyword"] <1>
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}
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--------------------------------------------------
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// CONSOLE
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<1> Set "keyword" to output "keyword" attribute only
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The request returns the following result:
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[source,js]
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--------------------------------------------------
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{
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"detail" : {
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"custom_analyzer" : true,
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"charfilters" : [ ],
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"tokenizer" : {
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"name" : "standard",
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"tokens" : [ {
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"token" : "detailed",
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"start_offset" : 0,
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"end_offset" : 8,
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"type" : "<ALPHANUM>",
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"position" : 0
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}, {
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"token" : "output",
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"start_offset" : 9,
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"end_offset" : 15,
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"type" : "<ALPHANUM>",
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"position" : 1
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} ]
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},
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"tokenfilters" : [ {
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"name" : "snowball",
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"tokens" : [ {
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"token" : "detail",
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"start_offset" : 0,
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"end_offset" : 8,
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"type" : "<ALPHANUM>",
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"position" : 0,
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"keyword" : false <1>
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}, {
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"token" : "output",
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"start_offset" : 9,
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"end_offset" : 15,
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"type" : "<ALPHANUM>",
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"position" : 1,
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"keyword" : false <1>
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} ]
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} ]
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}
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}
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--------------------------------------------------
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// TESTRESPONSE
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<1> Output only "keyword" attribute, since specify "attributes" in the request.
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[[tokens-limit-settings]]
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[float]
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== Settings to prevent tokens explosion
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Generating excessive amount of tokens may cause a node to run out of memory.
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The following setting allows to limit the number of tokens that can be produced:
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`index.analyze.max_token_count`::
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The maximum number of tokens that can be produced using `_analyze` API.
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The default value is `10000`. If more than this limit of tokens gets
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generated, an error will be thrown. The `_analyze` endpoint without a specified
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index will always use `10000` value as a limit. This setting allows you to control
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the limit for a specific index:
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[source,js]
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--------------------------------------------------
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PUT analyze_sample?include_type_name=true
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{
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"settings" : {
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"index.analyze.max_token_count" : 20000
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}
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}
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--------------------------------------------------
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// CONSOLE
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[source,js]
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--------------------------------------------------
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GET analyze_sample/_analyze
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{
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"text" : "this is a test"
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}
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--------------------------------------------------
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// CONSOLE
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// TEST[setup:analyze_sample] |