How to use the @theia/editor/lib/browser.Range.is function in @theia/editor

protected parentContains(candidate: DocumentSymbol | Range, parent: DocumentSymbol | Range, rangeBased: boolean): boolean {
        // TODO: move this code to the `monaco-languageclient`: https://github.com/theia-ide/theia/pull/2885#discussion_r217800446
        const candidateRange = Range.is(candidate) ? candidate : this.getFullRange(candidate);
        const parentRange = Range.is(parent) ? parent : this.getFullRange(parent);
        const sameStartLine = candidateRange.start.line === parentRange.start.line;
        const startColGreaterOrEqual = candidateRange.start.character >= parentRange.start.character;
        const startLineGreater = candidateRange.start.line > parentRange.start.line;
        const sameEndLine = candidateRange.end.line === parentRange.end.line;
        const endColSmallerOrEqual = candidateRange.end.character <= parentRange.end.character;
        const endLineSmaller = candidateRange.end.line < parentRange.end.line;
        return (((sameStartLine && startColGreaterOrEqual || startLineGreater) &&
            (sameEndLine && endColSmallerOrEqual || endLineSmaller)) || !rangeBased);
    }

protected parentContains(candidate: DocumentSymbol | Range, parent: DocumentSymbol | Range, rangeBased: boolean): boolean {
        // TODO: move this code to the `monaco-languageclient`: https://github.com/theia-ide/theia/pull/2885#discussion_r217800446
        const candidateRange = Range.is(candidate) ? candidate : this.getFullRange(candidate);
        const parentRange = Range.is(parent) ? parent : this.getFullRange(parent);
        const sameStartLine = candidateRange.start.line === parentRange.start.line;
        const startColGreaterOrEqual = candidateRange.start.character >= parentRange.start.character;
        const startLineGreater = candidateRange.start.line > parentRange.start.line;
        const sameEndLine = candidateRange.end.line === parentRange.end.line;
        const endColSmallerOrEqual = candidateRange.end.character <= parentRange.end.character;
        const endLineSmaller = candidateRange.end.line < parentRange.end.line;
        return (((sameStartLine && startColGreaterOrEqual || startLineGreater) &&
            (sameEndLine && endColSmallerOrEqual || endLineSmaller)) || !rangeBased);
    }