'Returns the absolute value of the operand.
If the operand is negative, the result is the same as using the minus
operation on the operand.  Otherwise, the result is the same as using
the plus operation on the operand.
>>> ExtendedContext.abs(Decimal(\'2.1\'))
Decimal(\'2.1\')
>>> ExtendedContext.abs(Decimal(\'-100\'))
Decimal(\'100\')
>>> ExtendedContext.abs(Decimal(\'101.5\'))
Decimal(\'101.5\')
>>> ExtendedContext.abs(Decimal(\'-101.5\'))
Decimal(\'101.5\')
>>> ExtendedContext.abs(-1)
Decimal(\'1\')'

def abs(self, a):

    a = _convert_other(a, raiseit=True)
    return a.__abs__(context=self)
