new_contents: # coding: utf-8
  from __future__ import unicode_literals
  
  from ..tokens import Doc
  from ..attrs import ORTH, POS, HEAD, DEP
  
  
  def get_doc(vocab, words, tags=None, heads=None, deps=None):
      """Create Doc object from given vocab, words and annotations."""
      tags = tags or [''] * len(words)
      heads = heads or [0] * len(words)
      deps = deps or [''] * len(words)
  
      doc = Doc(vocab, words=words)
      attrs = doc.to_array([POS, HEAD, DEP])
      for i, (tag, head, dep) in enumerate(zip(tags, heads, deps)):
          attrs[i, 0] = doc.vocab.strings[tag]
          attrs[i, 1] = head
          attrs[i, 2] = doc.vocab.strings[dep]
      doc.from_array([POS, HEAD, DEP], attrs)
      return doc
  
subject: Add test utils and get_doc helper function