ef METHOD_NAME( start, stop, step ):
  """Generate a range of Epoch objects.
  Similar to the Python range() method.  Returns the range [
  start, stop ) at the requested step.  Each element will be a
  Epoch object.
  = INPUT VARIABLES
  - start    The starting value of the range.
  - stop     The stop value of the range.
  - step     Step to use.
  = RETURN VALUE
  - Returns a list contianing the requested Epoch values.
  """
  elems = []
  i = 0
  while True:
     d = start + i * step
     if d >= stop:
        break
     elems.append( d )
     i += 1
  return elems