new_contents: """
      This file is part of flatlib - (C) FlatAngle
      Author: João Ventura (flatangleweb@gmail.com)
      
  
      This module provides useful functions for 
      handling solar and lunar returns.
      It only handles solar returns for now.
      
  """
  
  from flatlib import const
  from flatlib.ephem import ephem
  from flatlib.chart import Chart
  
  
  
  def _computeChart(chart, date):
      """ Internal function to return a new chart for
      a specific date using properties from old chart.
      
      """
      pos = chart.pos
      hsys = chart.hsys
      IDs = [obj.id for obj in chart.objects]
      return Chart(date, pos, IDs=IDs, hsys=hsys)
  
  def nextSolarReturn(chart, date):
      """ Returns the solar return of a Chart
      after a specific date.
      
      """
      sun = chart.getObject(const.SUN)
      srDate = ephem.nextSolarReturn(date, sun.lon)
      return _computeChart(chart, srDate)
  
  def prevSolarReturn(chart, date):
      """ Returns the solar return of a Chart
      before a specific date.
      
      """
      sun = chart.getObject(const.SUN)
      srDate = ephem.prevSolarReturn(date, sun.lon)
      return _computeChart(chart, srDate)
subject: Add returns to predictives