getFilter method
Gets the filter function registered with the given name.
This method retrieves a filter function from the FilterRegistry by the
specified name. If the filter is not found, it returns null.
@param name The name of the filter function to retrieve.
@return The filter function registered with the given name, or null if not found.
Implementation
FilterFunction? getFilter(String name) {
return FilterRegistry.getFilter(name);
}