keras/src/layers/core/einsum_dense.py/EinsumDense/call
class EinsumDense:    def call(self, inputs, training=None):
        x = ops.einsum(self.equation, inputs, self.kernel)
        if self.bias is not None:
            x += self.bias
        if self.activation is not None:
            x = self.activation(x)
        return x