assert (parameter);
Session::SourceMap::const_iterator i = sources.find (PBD::ID (source->value()));
assert (i != sources.end());
_source = boost::dynamic_pointer_cast<MidiSource> (i->second);
assert (parameter);
Session::SourceMap::const_iterator i = sources.find (PBD::ID (source->value()));
assert (i != sources.end());
_source = boost::dynamic_pointer_cast<MidiSource> (i->second);