def assoc_values(*others)
      all_keys = keys
      others.each { |hash| all_keys.concat(hash.keys) }
      all_keys.to_compact_hash do |k|
        others.map { |other| other[k] }.unshift(self[k])
      end
    end
def assoc_values(*others)
      all_keys = keys
      others.each { |hash| all_keys.concat(hash.keys) }
      all_keys.to_compact_hash do |k|
        others.map { |other| other[k] }.unshift(self[k])
      end
    end
Returns a hash which associates each key in this hash with the value mapped by the others.

 @example
   {:a => 1, :b => 2}.assoc_values({:a => 3, :c => 4}) #=> {:a => [1, 3], :b => [2, nil], :c => [nil, 4]}
   {:a => 1, :b => 2}.assoc_values({:a => 3}, {:a => 4, :b => 5}) #=> {:a => [1, 3, 4], :b => [2, nil, 5]}

 @param [<Hasher>] others the other Hashers to associate with this Hasher
 @return [Hash] the association hash