parameters: (self, key, value, prefix=0)
docstring: Add a header line to the MIME message.
  
          The key is the name of the header, where the value obviously provides
          the value of the header. The optional argument prefix determines
          where the header is inserted; 0 means append at the end, 1 means
          insert at the start. The default is to append.
docstring_summary: Add a header line to the MIME message.
docstring_tokens: Add a header line to the MIME message .
function: def addheader(self, key, value, prefix=0):
          """Add a header line to the MIME message.
  
          The key is the name of the header, where the value obviously provides
          the value of the header. The optional argument prefix determines
          where the header is inserted; 0 means append at the end, 1 means
          insert at the start. The default is to append.
  
          """
          lines = value.split("\n")
          while lines and not lines[-1]: del lines[-1]
          while lines and not lines[0]: del lines[0]
          for i in range(1, len(lines)):
              lines[i] = "    " + lines[i].strip()
          value = "\n".join(lines) + "\n"
          line = key + ": " + value
          if prefix:
              self._headers.insert(0, line)
          else:
              self._headers.append(line)
function_tokens: def addheader ( self , key , value , prefix = 0 ) : lines = value . split ( "\n" ) while lines and not lines [ - 1 ] : del lines [ - 1 ] while lines and not lines [ 0 ] : del lines [ 0 ] for i in range ( 1 , len ( lines ) ) : lines [ i ] = "    " + lines [ i ] . strip ( ) value = "\n" . join ( lines ) + "\n" line = key + ": " + value if prefix : self . _headers . insert ( 0 , line ) else : self . _headers . append ( line )