code: public Column getColumn(String columnName) {
      if (columnName == null) {
        return null;
      }
      for (Column column : columns) {
        if (columnName.equals(column.getData())) {
          return column;
        }
      }
      return null;
    }
docs: Find a column by its name
  
  @param columnName the name of the column
  @return the given Column, or <code>null</code> if not found