code: function insertColumnNames(line) {
    var columnNamesArr = line.split(this.seperator);
    var columnNames = '(';
    for (var i = 0; i < columnNamesArr.length; i++) {
      columnNames += columnNamesArr[i] + ',';
    }
    //remove trailing comma
    columnNames = columnNames.substring(0, columnNames.length - 1);
    columnNames += ')';
  
    var insert = 'INSERT INTO ' + this.tableName + ' ' + columnNames + ' ' +
      'VALUES';
  
    this.isFirstRowColumnNames = false;
  
    return insert;
  }
docs: /* helper