class_docstr: Affine warp constraints class.
  
  `AffineWarpConstraints` allow for
  very succinct definitions of constraints on
  the values of entries in affine transform matrices.
docstr: Empty set of constraints for a num_dim affine transform.
docstr_tok: ["Empty","set","of","constraints","for","a","num_dim","affine","transform","."]
code: def no_constraints(cls, num_dim=2):
      """
      Empty set of constraints for a num_dim affine transform.
      """
      return cls(((None,) * (num_dim + 1),) * num_dim)
  
imports: from __future__ import absolute_import, division, print_function
  from itertools import chain
  import numpy
  import tensorflow
  from niftynet.layer.base_layer import Layer, LayerFromCallable, Invertible
label_desc: Use image node_id 10 for calling the AffineWarpConstraints obj's underlying member method code with example usage: obj.no_constraints(cls, num_dim) and returns: cls