'Retrieve the raw string value for the given header.
Args:
name (str): Header name, case-insensitive. Must be of type ``str``
or ``StringType``, and only character values 0x00 through 0xFF
may be used on platforms that use wide characters.
Returns:
str: The header\'s value if set, otherwise ``None``.'

def get_header(self, name):

    return self._headers.get(name.lower(), None)
