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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _verify_barycentric(lambda1, lambda2, lambda3):
 """Verifies that weights are barycentric and on the reference triangle. I.e., checks that they sum to one and are all non-negative. Args: lambda1 (float):
 Parameter along the reference triangle. lambda2 (float):
 Parameter along the reference triangle. lambda3 (float):
 Parameter along the reference triangle. Raises: ValueError: If the weights are not valid barycentric coordinates, i.e. they don't sum to ``1``. ValueError: If some weights are negative. """

        weights_total = lambda1 + lambda2 + lambda3
        if not np.allclose(weights_total, 1.0, atol=0.0):
            raise ValueError(
                "Weights do not sum to 1", lambda1, lambda2, lambda3
            )

        if lambda1 < 0.0 or lambda2 < 0.0 or lambda3 < 0.0:
            raise ValueError(
                "Weights must be positive", lambda1, lambda2, lambda3
            )