src/vs/workbench/services/textMate/common/TMScopeRegistry.ts/TMScopeRegistry/register
class TMScopeRegistry:	public register(def: IValidGrammarDefinition): void {
		if (this._scopeNameToLanguageRegistration[def.scopeName]) {
			const existingRegistration = this._scopeNameToLanguageRegistration[def.scopeName];
			if (!resources.isEqual(existingRegistration.location, def.location)) {
				console.warn(
					`Overwriting grammar scope name to file mapping for scope ${def.scopeName}.\n` +
					`Old grammar file: ${existingRegistration.location.toString()}.\n` +
					`New grammar file: ${def.location.toString()}`
				);
			}
		}
		this._scopeNameToLanguageRegistration[def.scopeName] = def;
	}