docstr: Get word masks of given textfield
  
  :param str field: field name
  :return: list of mask values
docstr_tok: ["Get","word","masks","of","given","textfield",":","param","str","field",":","field","name",":","return",":","list","of","mask","values"]
code: def get_mask(self, field):
      r"""
      Get word masks of given textfield
  
      :param str field: field name
      :return: list of mask values
  
      """
      field_obj = getattr(self, field)
      assert isinstance(
          field_obj, DPCnTextField
      ), f"{field} is not a dp text field, get mask failed!"
  
      return field_obj.mask[:]
  
imports: from .cnsample import CnSample
  from ..field import ListField, Field
  from ....common.settings import ORIGIN, TASK_MASK, MODIFIED_MASK
label_desc: Use image node_id 5 for calling the DPCnSample obj's underlying member method code with example usage: obj.get_mask(field) and returns: field_obj