intercepted function.ex

defmodule Foo do
  def bar(x, y) do
    start_time = :os.system_time(:microsecond)
    try do
      success_result = x / y
      Kernel.apply(Instrumentation,:success_callback,
        [
          {Foo, :bar, [x, y]},
          success_result,
          start_time
        ])
      success_result
    rescue
      error -> 
        Kernel.apply(Instrumentation,:error_callback,
          [
            {Foo, :bar, [x, y]},
            error,
            start_time
          ])
        reraise(error, __STACKTRACE__)
    end
  end
end