module Mocha::ParameterMatchers

def parse_option(option)
  case option
  when Hash
    case option.length
    when 0
      raise ArgumentError, 'Argument has no entries.'
    when 1
      option.first
    else
      raise ArgumentError, 'Argument has multiple entries. Use Mocha::ParameterMatchers#has_entries instead.'
    end
  else
    raise ArgumentError, 'Argument is not a Hash.'
  end
end