{Object} optional JSON configuration object, allows all the viewer settings to pass to the constructor and avoid calling individual setter methods. Contains the following properties:
containerId - {String} ID of the DOM container (normally a DIV ) that the viewer is inserted into. It is not necessary to have the container element created by the time this method is called. However, the container must exist when init() is run. Required.
params - {Object} JSON object with viewer configuration parameters where the property name is either a viewer-specific configuration option or an SDK modifier, and the value of that property is a corresponding settings value. Required.
handlers - {Object} JSON object with viewer event callbacks, where the property name is the name of supported viewer event, and the property value is a JavaScript function reference to an appropriate callback. Optional.