'Returns the list of indices of the tensor
The indices are listed in the order in which they appear in the
component tensors.
The dummy indices are given a name which does not collide with
the names of the free indices.
Examples
>>> from sympy.tensor.tensor import TensorIndexType, tensor_indices, tensorhead
>>> Lorentz = TensorIndexType(\'Lorentz\', dummy_fmt=\'L\')
>>> m0, m1, m2 = tensor_indices(\'m0,m1,m2\', Lorentz)
>>> g = Lorentz.metric
>>> p, q = tensorhead(\'p,q\', [Lorentz], [[1]])
>>> t = p(m1)*g(m0,m2)
>>> t.get_indices()
[m1, m0, m2]
>>> t2 = p(m1)*g(-m1, m2)
>>> t2.get_indices()
[L_0, -L_0, m2]'

def get_indices(self):

    return self._index_structure.get_indices()
