def matches(encoding)
      values.select {|v|
        v == encoding || v == '*'
      }.sort {|a, b|
        # "*" gets least precedence, any others should be equal.
        a == '*' ? 1 : (b == '*' ? -1 : 0)
      }
    end
def matches(encoding)
      values.select {|v|
        v == encoding || v == '*'
      }.sort {|a, b|
        # "*" gets least precedence, any others should be equal.
        a == '*' ? 1 : (b == '*' ? -1 : 0)
      }
    end
Returns an array of encodings from this header that match the given
 +encoding+, ordered by precedence.