'Decode a byte string into this Charstr.
@type strio: file
@param strio: Bytes will be read from this file until the full string
is decoded.
@raise EOFError: Raised when there are not enough bytes available from
C{strio}.'

def decode(self, strio, length=None):

    self.string = ''
    l = ord(readPrecisely(strio, 1))
    self.string = readPrecisely(strio, l)
