A Roland For An Oliver Meaning

(idiomatic) Equal measure; measure for measure; adequate response.

Example: 1825, William Hazlitt, The Spirit of the Age, Mr. Malthus
  Mr. Godwin has lately attempted an answer to the Essay (thus giving Mr. Malthus a Roland for his Oliver) but we think he has judged ill in endeavouring to invalidate the principle, instead of confining himself to point out the misapplication of it.
1881, Robert Louis Stevenson, Virginibus Puerisque
  It is held to be a good taunt, and somehow or other to clinch the question logically, when an old gentleman waggles his head and says: "Ah, so I thought when I was your age." It is not thought an answer at all, if the young man retorts: "My venerable sir, so I shall most probably think when I am yours." And yet the one is as good as the other: pass for pass, tit for tat, a Roland for an Oliver.
1919, W. Somerset Maugham, The Moon and Sixpence, chapter 40
  I had to bite my lip to prevent myself from laughing. What he said had a hateful truth in it, and another defect of my character is that I enjoy the company of those, however depraved, who can give me a Roland for my Oliver.