enterModule = (connection, runtimeCondition) => {
			const module = connection.module;
			if (!module) return;
			const existingEntry = existingEntries.get(module);
			if (existingEntry === true) {
				return;
			}
			if (modulesSet.has(module)) {
				existingEntries.set(module, true);
				if (runtimeCondition !== true) {
					throw new Error(
						`Cannot runtime-conditional concatenate a module (${module.identifier()} in ${this.rootModule.identifier()}, ${runtimeConditionToString(
							runtimeCondition
						)}). This should not happen.`
					);
				}
				const imports = getConcatenatedImports(module);
				for (const { connection, runtimeCondition } of imports)
					enterModule(connection, runtimeCondition);
				list.push({
					type: "concatenated",
					module: connection.module,
					runtimeCondition
				});
			} else {
				if (existingEntry !== undefined) {
					const reducedRuntimeCondition = subtractRuntimeCondition(
						runtimeCondition,
						existingEntry,
						runtime
					);
					if (reducedRuntimeCondition === false) return;
					runtimeCondition = reducedRuntimeCondition;
					existingEntries.set(
						connection.module,
						mergeRuntimeConditionNonFalse(
							existingEntry,
							runtimeCondition,
							runtime
						)
					);
				} else {
					existingEntries.set(connection.module, runtimeCondition);
				}
				if (list.length > 0) {
					const lastItem = list[list.length - 1];
					if (
						lastItem.type === "external" &&
						lastItem.module === connection.module
					) {
						lastItem.runtimeCondition = mergeRuntimeCondition(
							lastItem.runtimeCondition,
							runtimeCondition,
							runtime
						);
						return;
					}
				}
				list.push({
					type: "external",
					get module() {
						// We need to use a getter here, because the module in the dependency
						// could be replaced by some other process (i. e. also replaced with a
						// concatenated module)
						return connection.module;
					},
					runtimeCondition
				});
			}
		}
@param {ModuleGraphConnection} connection graph connection
@param {RuntimeSpec | true} runtimeCondition runtime condition
@returns {void}