parameters: (self, pred = None)
return_statement: return ''.join(headers)
docstring: Return the message's header text as a string.  If an
          argument is specified, it is used as a filter predicate to
          decide which headers to return (its argument is the header
          name converted to lower case).
docstring_summary: Return the message's header text as a string.  If an
          argument is specified, it is used as a filter predicate to
          decide which headers to return (its argument is the header
          name converted to lower case).
docstring_tokens: Return the message s header text as a string . If an argument is specified it is used as a filter predicate to decide which headers to return ( its argument is the header name converted to lower case ) .
function: def getheadertext(self, pred = None):
          """Return the message's header text as a string.  If an
          argument is specified, it is used as a filter predicate to
          decide which headers to return (its argument is the header
          name converted to lower case)."""
          if pred is None:
              return ''.join(self.headers)
          headers = []
          hit = 0
          for line in self.headers:
              if not line[0].isspace():
                  i = line.find(':')
                  if i > 0:
                      hit = pred(line[:i].lower())
              if hit: headers.append(line)
          return ''.join(headers)
function_tokens: def getheadertext ( self , pred = None ) : if pred is None : return '' . join ( self . headers ) headers = [ ] hit = 0 for line in self . headers : if not line [ 0 ] . isspace ( ) : i = line . find ( ':' ) if i > 0 : hit = pred ( line [ : i ] . lower ( ) ) if hit : headers . append ( line ) return '' . join ( headers )