code: def check_random_state(seed):
      """Turn seed into a np.random.RandomState instance
  
      If seed is None, return the RandomState singleton used by np.random.
      If seed is an int, return a new RandomState instance seeded with seed.
      If seed is already a RandomState instance, return it.
      Otherwise raise ValueError.
      """
      if seed is None or seed is np.random:
          return np.random.mtrand._rand
      if isinstance(seed, (numbers.Integral, np.integer)):
          return np.random.RandomState(seed)
      if isinstance(seed, np.random.RandomState):
          return seed
      raise ValueError(
          "%r cannot be used to seed a numpy.random.RandomState"
          " instance" % seed
      )
  
imports: import warnings
  import numbers
  import numpy
  import scipy.sparse
  from ..externals import six
  from ..utils.fixes import signature
  from .deprecation import deprecated
  from ..exceptions import DataConversionWarning
  from ..exceptions import NonBLASDotWarning
  from ..exceptions import NotFittedError
label_desc: Use image node_id 13 for calling a global function with example usage: check_random_state(seed) and returns: np, np, seed