code: function compileRelayQLTag(
    t: $FlowFixMe,
    path: Object,
    schemaProvider: GraphQLSchemaProvider,
    quasi: Object,
    documentName: string,
    propName: ?string,
    tagName: string,
    enableValidation: boolean,
    state: BabelState,
  ): Object {
    try {
      const fileOpts = (state.file && state.file.opts) || {};
      const transformer = getClassicTransformer(
        schemaProvider,
        state.opts || {},
        fileOpts,
      );
      return transformer.transform(t, quasi, {
        documentName,
        propName,
        tagName,
        enableValidation,
      });
    } catch (error) {
      throw path.buildCodeFrameError(createTransformError(error), Error);
    }
  }
docs: Given all the metadata about a found RelayQL tag, compile it and return
  the resulting Babel AST.