formats a given keystroke into a string concode_field_sep String CTRL_MODIFIER concode_elem_sep String ALT_MODIFIER concode_elem_sep String SHIFT_MODIFIER concode_elem_sep String MODIFIER_JOINER concode_elem_sep String ALT_GRAPH_MODIFIER concode_elem_sep String META_MODIFIER concode_field_sep String getKeyText concode_elem_sep boolean isActionEvent concode_elem_sep String getModifiersText