inject
Injects the given customStyleSheet string that represents a custom style sheet (CSS) into the document that is loaded in this browser instance.
If CSS property defined in the given customStyleSheet string already exists on the loaded HTML document, then the existing CSS property won't be overridden. The CSS properties defined in the given customStyleSheet string will be applied only if these properties aren't defined on the loaded document.
Parameters
custom Style Sheet
CSS code that will be injected into the document
Throws
when customStyleSheet is empty or blank