'Special case of add, adding 1eExponent
Since it is common, (rounding, for example) this adds
(sign)*one E self._exp to the number more efficiently than add.
For example:
Decimal(\'5.624e10\')._increment() == Decimal(\'5.625e10\')'

def _increment(self, round=1, context=None):

    if self._is_special:
        ans = self._check_nans(context=context)
        if ans:
            return ans
        return Decimal(self)
    L = list(self._int)
    L[(-1)] += 1
    spot = (len(L) - 1)
    while (L[spot] == 10):
        L[spot] = 0
        if (spot == 0):
            L[0:0] = [1]
            break
        L[(spot - 1)] += 1
        spot -= 1
    ans = Decimal((self._sign, L, self._exp))
    if (context is None):
        context = getcontext()
    if (round and (context._rounding_decision == ALWAYS_ROUND)):
        ans = ans._fix(context)
    return ans
