code: function _firstNotWs(doc, lineNum) {
          var text = doc.getLine(lineNum);
          if (text === null || text === undefined) {
              return 0;
          }
  
          return text.search(/\S|$/);
      }
docs: Return the column of the first non whitespace char in the given line.
  
  @private
  @param {!Document} doc
  @param {number} lineNum
  @returns {number} the column index or null