code: function _getFunctionName(hostEditor, pos) {
          var token = hostEditor._codeMirror.getTokenAt(pos, true);
  
          // If the pos is at the beginning of a name, token will be the
          // preceding whitespace or dot. In that case, try the next pos.
          if (!/\S/.test(token.string) || token.string === ".") {
              token = hostEditor._codeMirror.getTokenAt({line: pos.line, ch: pos.ch + 1}, true);
          }
  
          // Return valid function expressions only (function call or reference)
          if (!((token.type === "variable") ||
                (token.type === "variable-2") ||
                (token.type === "property"))) {
              return {
                  functionName: null,
                  reason: Strings.ERROR_JSQUICKEDIT_FUNCTIONNOTFOUND
              };
          }
  
          return {
              functionName: token.string,
              reason: null
          };
      }
docs: Return the token string that is at the specified position.
  
  @param hostEditor {!Editor} editor
  @param {!{line:number, ch:number}} pos
  @return {functionName: string, reason: string}