module AWS::SimpleDB::ExpectConditionOption

def expect_condition_opts(opts)
  expected = []
  opts.each do |name, value|
    case name
    when :if
      (expected_name, expected_value) = value.to_a.first
      expected << {
        :name => expected_name.to_s,
        :value => expected_value
      }
    when :unless, :unless_exists
      expected << {
        :name => value.to_s,
        :exists => false
      }
    end
  end
  expected.empty? ? {} : expected.first
end