message: Add asserts for LinearOperatorBlockDiag.
  All asserts are only dependent on the constituent operators due to properties of the direct sum.
diff: @@ -24,6 +24,7 @@ from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import check_ops
  +from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops.linalg import linear_operator
  from tensorflow.python.ops.linalg import linear_operator_util
  @@ -333,6 +334,18 @@ class LinearOperatorBlockDiag(linear_operator.LinearOperator):
  mat.set_shape(self.shape)
  return mat
  + def _assert_non_singular(self):
  + return control_flow_ops.group([
  + operator.assert_non_singular() for operator in self.operators])
  +
  + def _assert_self_adjoint(self):
  + return control_flow_ops.group([
  + operator.assert_self_adjoint() for operator in self.operators])
  +
  + def _assert_positive_definite(self):
  + return control_flow_ops.group([
  + operator.assert_positive_definite() for operator in self.operators])
  +
  def _split_input_into_blocks(self, x, axis=-1):
  """Split `x` into blocks matching `operators`'s `domain_dimension`.
  