human
Give me a the Python program you requested given the following:
Complete the below
def _req_environ_property(environ_field):

    ''''Set and retrieve value of the environ_field entry in self.environ.
    (Used by both request and response)'
    '''
assistant
#Here is the Python program you requested.
    def getter(self):
        return self.environ.get(environ_field, None)
    def setter(self, value):
        if isinstance(value, six.text_type):
            self.environ[environ_field] = value.encode('utf-8')
        else:
            self.environ[environ_field] = value
    return property(getter, setter, doc=('Get    and    set    the    %s    property    in    the    WSGI    environment' % environ_field))