void emit_flushdraw(char const *label);
void emit_visible(char const *label, bool is_visible);
void emit_invisible(char const *label);
void emit_visible(char const *label);
WMError do_transition(unsigned sequence_number);
void emit_flushdraw(char const *label);
void emit_visible(char const *label, bool is_visible);
void emit_invisible(char const *label);
void emit_visible(char const *label);
WMError do_transition(unsigned sequence_number);