def merge_attributes!(attributes)
      @attributes.merge!(attributes) do |_, v1, v2|
        v1 = v1.strip
        v2 = v2.strip
        v1_split = v1.shellsplit
        v2_split = v2.shellsplit
        if (v2_split - v1_split).empty? || v1_split.first(v2_split.size) == v2_split
          v1
        elsif v2_split.first(v1_split.size) == v1_split
          v2
        else
          "#{v1} #{v2}"
        end
      end
    end
def merge_attributes!(attributes)
      @attributes.merge!(attributes) do |_, v1, v2|
        v1 = v1.strip
        v2 = v2.strip
        v1_split = v1.shellsplit
        v2_split = v2.shellsplit
        if (v2_split - v1_split).empty? || v1_split.first(v2_split.size) == v2_split
          v1
        elsif v2_split.first(v1_split.size) == v1_split
          v2
        else
          "#{v1} #{v2}"
        end
      end
    end
Merges the given attributes hash while ensuring values are not duplicated.

 @param  [Hash] attributes
         The attributes hash to merge into @attributes.

 @return [void]