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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 topology_mdtraj(traj):
    '''Generate topology spec for the MolecularViewer from mdtraj.

    :param mdtraj.Trajectory traj: the trajectory
    :return: A chemview-compatible dictionary corresponding to the topology defined in mdtraj.

    '''
    import mdtraj as md

    top = {}
    top['atom_types'] = [a.element.symbol for a in traj.topology.atoms]
    top['atom_names'] = [a.name for a in traj.topology.atoms]
    top['bonds'] = [(a.index, b.index) for a, b in traj.topology.bonds]
    top['secondary_structure'] = md.compute_dssp(traj[0])[0]
    top['residue_types'] = [r.name for r in traj.topology.residues ]
    top['residue_indices'] = [ [a.index for a in r.atoms] for r in traj.topology.residues ]

    return top