'multiply multiplies two operands.
If either operand is a special value then the general rules apply.
Otherwise, the operands are multiplied together (\'long multiplication\'),
resulting in a number which may be as long as the sum of the lengths
of the two operands.
>>> ExtendedContext.multiply(Decimal(\'1.20\'), Decimal(\'3\'))
Decimal("3.60")
>>> ExtendedContext.multiply(Decimal(\'7\'), Decimal(\'3\'))
Decimal("21")
>>> ExtendedContext.multiply(Decimal(\'0.9\'), Decimal(\'0.8\'))
Decimal("0.72")
>>> ExtendedContext.multiply(Decimal(\'0.9\'), Decimal(\'-0\'))
Decimal("-0.0")
>>> ExtendedContext.multiply(Decimal(\'654321\'), Decimal(\'654321\'))
Decimal("4.28135971E+11")'

def multiply(self, a, b):

    return a.__mul__(b, context=self)
