def replace_values old_values, new_value
      old_values = [old_values] unless old_values.is_a? Array
      rename_hash = old_values.map { |v| [v, new_value] }.to_h
      rename_categories rename_hash
    end
Replaces specified values with a new value
@param [Array] old_values array of values to replace
@param [object] new_value new value to replace with
@note It performs the replace in place.
@return [Daru::Vector] Same vector itself with values
replaced with new value
@example
dv = Daru::Vector.new [1, 2, :a, :b]
dv.replace_values [:a, :b], nil
dv
# =>
# #<Daru::Vector:19903200 @name = nil @metadata = {} @size = 4 >
#     nil
#   0   1
#   1   2
#   2 nil
#   3 nil