code: public Block withEntityTypes(String... entityTypes) {
          if (this.entityTypes == null) {
              setEntityTypes(new java.util.ArrayList<String>(entityTypes.length));
          }
          for (String ele : entityTypes) {
              this.entityTypes.add(ele);
          }
          return this;
      }
docs: <p>
  The type of entity. The following can be returned:
  </p>
  <ul>
  <li>
  <p>
  <i>KEY</i> - An identifier for a field on the document.
  </p>
  </li>
  <li>
  <p>
  <i>VALUE</i> - The field text.
  </p>
  </li>
  </ul>
  <p>
  <code>EntityTypes</code> isn't returned by <code>DetectDocumentText</code> and
  <code>GetDocumentTextDetection</code>.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setEntityTypes(java.util.Collection)} or {@link #withEntityTypes(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param entityTypes
  The type of entity. The following can be returned:</p>
  <ul>
  <li>
  <p>
  <i>KEY</i> - An identifier for a field on the document.
  </p>
  </li>
  <li>
  <p>
  <i>VALUE</i> - The field text.
  </p>
  </li>
  </ul>
  <p>
  <code>EntityTypes</code> isn't returned by <code>DetectDocumentText</code> and
  <code>GetDocumentTextDetection</code>.
  @return Returns a reference to this object so that method calls can be chained together.
  @see EntityType