Send a synthetic mouse button/release event. Create a synthetic event of a press of mouse button button. The usual mouse button specification format (with modifiers) is used. Send the event to window win if specified; otherwise the window to be used defaults to the window context in the usual way. By default, both a press and a release are sent---a click. kind can be one of 'press, 'release, 'click, 'desk-press, 'desk-release, or 'desk-click. If dx or dy is set, that value is used as the offset within win for the button events to occur. If one is not specified or #f, then the pointer offset of that coordinate is used instead. propagate? indicates whether the propagate flag is set on the event; the default is #f. You should not have to worry about this unless you know what it means.