@c snarfed from "mu_body.c":106
@deffn {Scheme procedure} mu-body-read-line body
Read next line from the @var{body}.
@end deffn

@c snarfed from "mu_body.c":167
@deffn {Scheme procedure} mu-body-write body text
Append @var{text} to message @var{body}.
@end deffn