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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 equiv(self, other):
 """Return True if other is an equivalent weighting. Returns ------- equivalent : bool ``True`` if ``other`` is a `Weighting` instance with the same `Weighting.impl`, which yields the same result as this weighting for any input, ``False`` otherwise. This is checked by entry-wise comparison of arrays/constants. """

        # Optimization for equality
        if self == other:
            return True
        elif (not isinstance(other, Weighting) or
              self.exponent != other.exponent):
            return False
        elif isinstance(other, MatrixWeighting):
            return other.equiv(self)
        elif isinstance(other, ConstWeighting):
            return np.array_equiv(self.array, other.const)
        else:
            return np.array_equal(self.array, other.array)