### Problem Calling `FooterToolbarGridHelper#setFooterToolbar` with a `null` toolbar causes a `NullPointerException`. ### Proposed fix Add `Objects.requireNonNull(toolBar, "Toolbar component must not be null")` at the start of the method and import `java.util.Objects`. ### Context Raised during code review of PR #130. PR: https://github.com/FlowingCode/GridHelpers/pull/130 Review comment: https://github.com/FlowingCode/GridHelpers/pull/130#discussion_r2140398812 --- _Reported by CodeRabbit review bot as requested by @javier-godoy_.