def check_booleans!
      booleans_hash.each do |key, value|
        unless BOOLEANS.include?(value)
          raise ArgumentError, "Expected `#{key}` to be either true, false or nil, got #{value}"
        end
      end
    end
def check_booleans!
      booleans_hash.each do |key, value|
        unless BOOLEANS.include?(value)
          raise ArgumentError, "Expected `#{key}` to be either true, false or nil, got #{value}"
        end
      end
    end
Checks all boolean arguments
 @raise ArgumentError