code: function getColumnType(columnDefinitions, columnName) {
      Validate.isObject(columnDefinitions);
      Validate.notNull(columnDefinitions);
      Validate.isString(columnName);
      Validate.notNullOrEmpty(columnName);
  
      for (var column in columnDefinitions) {
          if (column.toLowerCase() === columnName.toLowerCase()) {
              return columnDefinitions[column];
          }
      }
  }
docs: Gets the type of the specified column
  @private