part of fix for type checking

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/StructureDefinition.java

@@ -1245,6 +1245,20 @@ public class StructureDefinition extends CanonicalResource {
     return null;
   }
 
+
+  public ElementDefinition getElementById(String id) {
+    if (id == null) {
+      return null;
+    }
+    for (ElementDefinition ed : getElement()) {
+      if (id.equals(ed.getId())) {
+        return ed;
+      }
+    }
+    return null;
+  }
+
+  
 // end addition
   }