Heredoc's getContentRange() has an incorrect starting line if the content is just empty lines

[rcjsuen]

RUN <<EOT

EOT

const lib = require("dockerfile-ast");
const instruction = lib.DockerfileParser.parse("RUN <<EOT\n\nEOT").getInstructions()[0];
console.log(instruction.getHeredocs()[0].getContentRange().start.line);

2

It should be 1 instead.