code: def _rbl(rate, per, pmt, pv, when):
      """
      This function is here to simply have a different name for the 'fv'
      function to not interfere with the 'fv' keyword argument within the 'ipmt'
      function.  It is the 'remaining balance on loan' which might be useful as
      it's own function, but is easily calculated with the 'fv' function.
      """
      return fv(rate, (per - 1), pmt, pv, when)
  
imports: from __future__ import division, absolute_import, print_function
  from decimal import Decimal
  import functools
  import numpy
  from numpy.core import overrides
label_desc: Use image node_id 10 for calling a global function with example usage: _rbl(rate, per, pmt, pv, when) and returns: fv