[TextDocument.getText](https://github.com/Microsoft/vscode-languageserver-node/blob/master/types/src/main.ts#L1355) method should accept Range as an optional parameter. This refers to https://code.visualstudio.com/docs/extensionAPI/vscode-api#_a-nametextdocumentaspan-classcodeitem-id38textdocumentspan