code: func (a int64Amount) AsInt64() (int64, bool) {
  	if a.scale == 0 {
  		return a.value, true
  	}
  	if a.scale < 0 {
  		// TODO: attempt to reduce factors, although it is assumed that factors are reduced prior
  		// to the int64Amount being created.
  		return 0, false
  	}
  	return positiveScaleInt64(a.value, a.scale)
  }
docs: // AsInt64 returns the current amount as an int64 at scale 0, or false if the value cannot be
  // represented in an int64 OR would result in a loss of precision. This method is intended as
  // an optimization to avoid calling AsDec.