'Returns the value of the argument with the given name
from the request body.
If default is not provided, the argument is considered to be
required, and we raise a `MissingArgumentError` if it is missing.
If the argument appears in the url more than once, we return the
last value.
The returned value is always unicode.
.. versionadded:: 3.2'

def get_body_argument(self, name, default=_ARG_DEFAULT, strip=True):

    return self._get_argument(name, default, self.request.body_arguments, strip)
