code: def test_column_field():
      schema = fields.Schema(
          a=fields.TEXT(sortable=True),
          b=fields.COLUMN(columns.RefBytesColumn()),
      )
      with TempIndex(schema, "columnfield") as ix:
          with ix.writer(codec=W3Codec()) as w:
              w.add_document(a=u("alfa bravo"), b=b("charlie delta"))
              w.add_document(a=u("bravo charlie"), b=b("delta echo"))
              w.add_document(a=u("charlie delta"), b=b("echo foxtrot"))
  
          with ix.reader() as r:
              assert r.has_column("a")
              assert r.has_column("b")
  
              cra = r.column_reader("a")
              assert cra[0] == u("alfa bravo")
              assert type(cra[0]) == text_type
  
              crb = r.column_reader("b")
              assert crb[0] == b("charlie delta")
              assert type(crb[0]) == bytes_type
  
file_path: whoosh/tests/test_columns.py
imports: from __future__ import with_statement
  import inspect, random, sys
  from whoosh import columns, fields, query
  from whoosh.codec.whoosh3 import W3Codec
  from whoosh.compat import b, u, BytesIO, bytes_type, text_type
  from whoosh.compat import izip, xrange, dumps, loads
  from whoosh.filedb import compound
  from whoosh.filedb.filestore import RamStorage
  from whoosh.util.testing import TempIndex, TempStorage
label_desc: Use image node_id 7 for calling a global function with example usage: test_column_field() without return types