code: def get_content_length(environ):
      
      content_length = environ.get('CONTENT_LENGTH')
      if content_length is not None:
          try:
              return max(0, int(content_length))
          except (ValueError, TypeError):
              pass
docs: Returns the content length from the WSGI environment as
      integer.  If it's not available `None` is returned.
  
      .. versionadded:: 0.9
  
      :param environ: the WSGI environ to fetch the content length from.