How to use the @dataform/core/utils.flatten function in @dataform/core

export function mapToColumnProtoArray(columns: IColumnsDescriptor): dataform.IColumnDescriptor[] {
  return utils.flatten(
    Object.keys(columns).map(column => mapColumnDescriptionToProto([column], columns[column]))
  );
}

description,
        path: currentPath
      })
    ];
  }
  const columnDescriptor: dataform.IColumnDescriptor[] = description.description
    ? [
        dataform.ColumnDescriptor.create({
          description: description.description,
          path: currentPath
        })
      ]
    : [];
  const nestedColumns = description.columns ? Object.keys(description.columns) : [];
  return columnDescriptor.concat(
    utils.flatten(
      nestedColumns.map(nestedColumn =>
        mapColumnDescriptionToProto(
          currentPath.concat([nestedColumn]),
          description.columns[nestedColumn]
        )
      )
    )
  );
}

description,
        path: currentPath
      })
    ];
  }
  const columnDescriptor: dataform.IColumnDescriptor[] = description.description
    ? [
        dataform.ColumnDescriptor.create({
          description: description.description,
          path: currentPath
        })
      ]
    : [];
  const nestedColumns = description.columns ? Object.keys(description.columns) : [];
  return columnDescriptor.concat(
    utils.flatten(
      nestedColumns.map(nestedColumn =>
        mapColumnDescriptionToProto(
          currentPath.concat([nestedColumn]),
          description.columns[nestedColumn]
        )
      )
    )
  );
}

export function mapToColumnProtoArray(columns: IColumnsDescriptor): dataform.IColumnDescriptor[] {
  return utils.flatten(
    Object.keys(columns).map(column => mapColumnDescriptionToProto([column], columns[column]))
  );
}