def METHOD_NAME(self, name='G', **kwds):
    r"""
    Return the Lie group associated to ``self``.
    INPUT:
    - ``name`` -- string (default: ``'G'``);
      the name (symbol) given to the Lie group
    EXAMPLES:
    We define the Heisenberg group::
        sage: L = lie_algebras.Heisenberg(QQ, 1)                                # needs sage.combinat sage.modules
        sage: G = L.lie_group('G'); G                                           # needs sage.combinat sage.modules sage.symbolic
        Lie group G of Heisenberg algebra of rank 1 over Rational Field
    We test multiplying elements of the group::
        sage: # needs sage.combinat sage.modules sage.symbolic
        sage: p, q, z = L.basis()
        sage: g = G.exp(p); g
        exp(p1)
        sage: h = G.exp(q); h
        exp(q1)
        sage: g * h
        exp(p1 + q1 + 1/2*z)
    We extend an element of the Lie algebra to a left-invariant
    vector field::
        sage: X = G.left_invariant_extension(2*p + 3*q, name='X'); X            # needs sage.combinat sage.modules sage.symbolic
        Vector field X on the Lie group G of
         Heisenberg algebra of rank 1 over Rational Field
        sage: X.at(G.one()).display()                                           # needs sage.combinat sage.modules sage.symbolic
        X = 2 ∂/∂x_0 + 3 ∂/∂x_1
        sage: X.display()                                                       # needs sage.combinat sage.modules sage.symbolic
        X = 2 ∂/∂x_0 + 3 ∂/∂x_1 + (3/2*x_0 - x_1) ∂/∂x_2
    .. SEEALSO::
        :class:`~sage.groups.lie_gps.nilpotent_lie_group.NilpotentLieGroup`
    """
    from sage.groups.lie_gps.nilpotent_lie_group import NilpotentLieGroup
    return NilpotentLieGroup(self, name, **kwds)