get(module, runtime) {
		const entry = this.map.get(module);
		if (entry === undefined) {
			throw new Error(
				`No code generation entry for ${module.identifier()} (existing entries: ${Array.from(
					this.map.keys(),
					m => m.identifier()
				).join(", ")})`
			);
		}
		if (runtime === undefined) {
			if (entry.size > 1) {
				const results = new Set(entry.values());
				if (results.size !== 1) {
					throw new Error(
						`No unique code generation entry for unspecified runtime for ${module.identifier()} (existing runtimes: ${Array.from(
							entry.keys(),
							r => runtimeToString(r)
						).join(", ")}).
Caller might not support runtime-dependent code generation (opt-out via optimization.usedExports: "global").`
					);
				}
				return /** @type {CodeGenerationResult} */ (first(results));
			}
			return /** @type {CodeGenerationResult} */ (entry.values().next().value);
		}
		const result = entry.get(runtime);
		if (result === undefined) {
			throw new Error(
				`No code generation entry for runtime ${runtimeToString(
					runtime
				)} for ${module.identifier()} (existing runtimes: ${Array.from(
					entry.keys(),
					r => runtimeToString(r)
				).join(", ")})`
			);
		}
		return result;
	}
@param {Module} module the module
@param {RuntimeSpec} runtime runtime(s)
@returns {CodeGenerationResult} the CodeGenerationResult