class_docstr: Constrains the weights to be non-negative.
  
  Also available via the shortcut function `tf.keras.constraints.non_neg`.
code: def __call__(self, w):
      return w * math_ops.cast(
          math_ops.greater_equal(w, 0.0), backend.floatx()
      )
  
imports: from tensorflow.python.framework import tensor_shape
  from tensorflow.python.keras import backend
  from tensorflow.python.keras.utils.generic_utils import deserialize_keras_object
  from tensorflow.python.keras.utils.generic_utils import serialize_keras_object
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import while_loop
  from tensorflow.tools.docs import doc_controls
label_desc: Use image node_id 1 for calling the NonNeg obj's underlying member method code with example usage: obj.__call__(w) and returns: unknown