code: def _input_with_indice_as_values(length, dim):
      """Retuns np.array of size (1, length, dim) where x[0, a, b] = a."""
      positions = []
      for i in range(length):
          positions.append([i] * dim)
      positions_input = np.array(positions)
      positions_input = np.expand_dims(positions_input, axis=0)
      return positions_input
  
file_path: trax/trax/models/research/rse_test.py
imports: from absl.testing import absltest
  import numpy
  from trax import shapes
  from trax.models.research import rse
label_desc: Use image node_id 1 for calling a global function with example usage: _input_with_indice_as_values(length, dim) and returns: positions_input