code: def _default_step_sizes(reference_vertex):
      """Chooses default step sizes according to [Gao and Han(2010)][3]."""
      # Step size to choose when the coordinate is zero.
      small_sizes = dtype_util.as_numpy_dtype(reference_vertex.dtype)(
          0.00025
      )
      # Step size to choose when the coordinate is non-zero.
      large_sizes = reference_vertex * 0.05
      return tf.where(
          tf.abs(reference_vertex) < _EPSILON, small_sizes, large_sizes
      )
  
imports: import collections
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import dtype_util
  from tensorflow_probability.python.internal import prefer_static
  from tensorflow_probability.python.internal import tensorshape_util
label_desc: Use image node_id 11 for calling a global function with example usage: _default_step_sizes(reference_vertex) and returns: tf