title: Hot to get date range filter value? (min and max)
body: <p>I use IronPython script to get some values from some filter(all are ListBoxFilter)
  please see below code</p>
  
  <pre><code>from Spotfire.Dxp.Application.Filters import *
  from Spotfire.Dxp.Application.Visuals import HtmlTextArea
  from System import DateTime
  from Spotfire.Dxp.Data.DataType import Date
  
  html.As[HtmlTextArea]().HtmlContent=""
  
  list=[]
  GRF=pg.FilterPanel.TableGroups[0].GetFilter("GEOGRAPHIC_REGION").FilterReference.As[ListBoxFilter]()
  for value in GRF.SelectedValues:
      if value.find(',')!=-1:
      list.append(value)
  PTF=pg.FilterPanel.TableGroups[0].GetFilter("PROCEDURE_TYPE").FilterReference.As[ListBoxFilter]()
  for value in PTF.SelectedValues:
      if value.find(',')!=-1:
      list.append(value)
  </code></pre>
  
  <p>if I want to get a range filter's value(min and max) and add them(min and max) to one item in the list, how to code? please help</p>