Range of argument ending with a character preceded by an escape character is off

[rcjsuen]

RUN "\
\
\"

import { DockerfileParser } from 'dockerfile-ast';

let dockerfile = DockerfileParser.parse("RUN \"\\\n\\\n\\\"");
let instruction = dockerfile.getInstructions()[0];
let argument = instruction.getArguments()[0];
console.log(argument.getRange());

{ start: { line: 0, character: 4 },
  end: { line: 1, character: 0 } }

The end position should point at { line: 2, position: 2 } instead given that it ends on the third line and not the second.