code: public final void writeBooleanField(String fieldName, boolean value)
          throws IOException, JsonGenerationException
      {
          writeFieldName(fieldName);
          writeBoolean(value);
      }
docs: Convenience method for outputting a field entry ("member")
  that has a boolean value. Equivalent to:
  <pre>
  writeFieldName(fieldName);
  writeBoolean(value);
  </pre>