message: Update ragged_boolean_mask_op_test.py
  typo
diff: @@ -316,7 +316,7 @@ class RaggedBooleanMaskOpTest(ragged_test_util.RaggedTensorTestCase,
  def testErrors(self):
  if not context.executing_eagerly():
  self.assertRaisesRegexp(ValueError,
  - r'mask\.shape\.ndims must be kown statically',
  + r'mask\.shape\.ndims must be known statically',
  ragged_array_ops.boolean_mask, [[1, 2]],
  array_ops.placeholder(dtypes.bool))
  