'Returns `True` if this unit is equivalent to ``other``.
Parameters
other : unit object or string or tuple
The unit to convert to. If a tuple of units is specified, this
method returns true if the unit matches any of those in the tuple.
equivalencies : list of equivalence pairs, optional
A list of equivalence pairs to try if the units are not
directly convertible.  See :ref:`unit_equivalencies`.
This list is in addition to possible global defaults set by, e.g.,
`set_enabled_equivalencies`.
Use `None` to turn off all equivalencies.
Returns
bool'

def is_equivalent(self, other, equivalencies=[]):

    equivalencies = self._normalize_equivalencies(equivalencies)
    if isinstance(other, tuple):
        return any((self.is_equivalent(u, equivalencies=equivalencies) for u in other))
    other = Unit(other, parse_strict=u'silent')
    return self._is_equivalent(other, equivalencies)
