'Given a complete HTTP header, extract the field name and value and
process the header.
@param header: a complete HTTP request header of the form
\'field-name: value\'.
@type header: C{bytes}'

def extractHeader(self, header):

    (key, val) = header.split(':', 1)
    val = val.lstrip()
    self.handleHeader(key, val)
    if (key.lower() == 'content-length'):
        self.length = int(val)
