code: def relu(x, alpha=0.0, max_value=None, threshold=0):
      """Applies the rectified linear unit activation function.
  
      With default values, this returns the standard ReLU activation:
      `max(x, 0)`, the element-wise maximum of 0 and the input tensor.
  
      Modifying default parameters allows you to use non-zero thresholds,
      change the max value of the activation,
      and to use a non-zero multiple of the input for values below the threshold.
  
      For example:
  
      >>> foo = tf.constant([-10, -5, 0.0, 5, 10], dtype = tf.float32)
      >>> tf.keras.activations.relu(foo).numpy()
      array([ 0.,  0.,  0.,  5., 10.], dtype=float32)
      >>> tf.keras.activations.relu(foo, alpha=0.5).numpy()
      array([-5. , -2.5,  0. ,  5. , 10. ], dtype=float32)
      >>> tf.keras.activations.relu(foo, max_value=5).numpy()
      array([0., 0., 0., 5., 5.], dtype=float32)
      >>> tf.keras.activations.relu(foo, threshold=5).numpy()
      array([-0., -0.,  0.,  0., 10.], dtype=float32)
  
      Args:
          x: Input `tensor` or `variable`.
          alpha: A `float` that governs the slope for values lower than the
            threshold.
          max_value: A `float` that sets the saturation threshold (the largest value
            the function will return).
          threshold: A `float` giving the threshold value of the activation function
            below which values will be damped or set to zero.
  
      Returns:
          A `Tensor` representing the input tensor,
          transformed by the relu activation function.
          Tensor will be of the same shape and dtype of input `x`.
      """
      return backend.relu(
          x, alpha=alpha, max_value=max_value, threshold=threshold
      )
  
imports: from tensorflow.python.keras import backend
  from tensorflow.python.keras.layers import advanced_activations
  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 math_ops
  from tensorflow.python.ops import nn
  from tensorflow.python.util import dispatch
label_desc: Use image node_id 7 for calling a global function with example usage: relu(x, alpha, max_value, threshold) and returns: backend