Add "tap" tool to a Bokeh figure
tool_tap(fig, callback, ref_layer)
| fig | figure to modify | 
|---|---|
| callback | a callback to be applied to this tool - either a character string of javascript code or any one of  | 
| ref_layer | name of the layer that the callback should be applied to | 
Tools can be easily specified as a vector of tool names in the tools argument when instantiating a figure.  In this case, they are added with defaults.  Explicitly calling these tool_ functions will manually add the tool to a figure and allow additional specification of parameters.
Other tools: 
tool_box_select(),
tool_box_zoom(),
tool_crosshair(),
tool_hover(),
tool_lasso_select(),
tool_pan(),
tool_reset(),
tool_resize(),
tool_save(),
tool_wheel_zoom()
# \donttest{ figure() %>% ly_points(1:10, lname = "points") %>% tool_tap(debug_callback("points"), "points") # }