This function returns the command bound to the key specified by keyexpr for the keyboard shortcut specified by keymap. keyexpr is the same as the keyname argument to the map command (for example, Control+Shift+A). keymap is the same as the window argument to map and is a window class (for example, edit, cmd, or helpwin), a window name as returned by the window_name function, or a user-defined keyboard shortcut denoted by the prefix character @ (for example, CTRL+S). If keymap is omitted, the keymap associated with the current window is used.