<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def valid_backbone_bond_lengths(self, atol=0.1):
 """True if all backbone bonds are within atol Angstroms of the expected distance. Notes ----- Ideal bond lengths taken from [1]. References .. [1] Schulz, G. E, and R. Heiner Schirmer. Principles Of Protein Structure. New York: Springer-Verlag, 1979. Parameters atol : float, optional Tolerance value in Angstoms for the absolute deviation away from ideal backbone bond lengths. """

        bond_lengths = self.backbone_bond_lengths
        a1 = numpy.allclose(bond_lengths['n_ca'],
                            [ideal_backbone_bond_lengths['n_ca']] * len(self),
                            atol=atol)
        a2 = numpy.allclose(bond_lengths['ca_c'],
                            [ideal_backbone_bond_lengths['ca_c']] * len(self),
                            atol=atol)
        a3 = numpy.allclose(bond_lengths['c_o'],
                            [ideal_backbone_bond_lengths['c_o']] * len(self),
                            atol=atol)
        a4 = numpy.allclose(bond_lengths['c_n'],
                            [ideal_backbone_bond_lengths['c_n']] *
                            (len(self) - 1),
                            atol=atol)
        return all([a1, a2, a3, a4])