[keras] adds WhereEquals Layer

keras.py

@@ -932,6 +932,18 @@ class AUCOneVsAll(tf.keras.metrics.AUC):
             )
 
 
+# Layer Definitions
+
+
+class WhereEquals(tf.keras.layers.Layer):
+    def __init__(self, value=0):
+        super(WhereEquals, self).__init__()
+        self.value = value
+
+    def call(self, inp):
+        return tf.where(inp[:, 0] == self.value)
+
+
 class DenseLayer(tf.keras.layers.Layer):
     """
     The DenseLayer object is an extended implementation of the tf.keras.layers.Dense.
@@ -1297,6 +1309,8 @@ def grouped_cross_entropy_t(
 
 
 # Custom Loss Functions
+
+
 class GroupedXEnt(tf.keras.losses.Loss):
     def __init__(
         self,