Only use for square 2D matrices.
initializer_identity(gain = 1)Multiplicative factor to apply to the identity matrix
Other initializers: initializer_constant,
initializer_glorot_normal,
initializer_glorot_uniform,
initializer_he_normal,
initializer_he_uniform,
initializer_lecun_normal,
initializer_lecun_uniform,
initializer_ones,
initializer_orthogonal,
initializer_random_normal,
initializer_random_uniform,
initializer_truncated_normal,
initializer_variance_scaling,
initializer_zeros