message: Add a refinement to squelch a bunch of Flow errors
  This drops the error count from 288 to 225.
diff: @@ -117,7 +117,8 @@ export class GraphQLLanguageService {
  }
  const node = getASTNodeAtPosition(query, ast, position);
  - switch (node ? node.kind : null) {
  + if (node) {
  + switch (node.kind) {
  case FRAGMENT_SPREAD:
  return this._getDefinitionForFragmentSpread(
  query,
  @@ -129,10 +130,14 @@ export class GraphQLLanguageService {
  );
  case FRAGMENT_DEFINITION:
  case OPERATION_DEFINITION:
  - return getDefinitionQueryResultForDefinitionNode(filePath, query, node);
  - default:
  - return null;
  + return getDefinitionQueryResultForDefinitionNode(
  + filePath,
  + query,
  + node,
  + );
  + }
  }
  + return null;
  }
  async _getDefinitionForFragmentSpread(
  