src/vs/workbench/api/common/extHostTypes.ts/CompletionItem/toJSON
class CompletionItem:	toJSON(): any {
		return {
			label: this.label,
			kind: this.kind && CompletionItemKind[this.kind],
			detail: this.detail,
			documentation: this.documentation,
			sortText: this.sortText,
			filterText: this.filterText,
			preselect: this.preselect,
			insertText: this.insertText,
			textEdit: this.textEdit
		};
	}