driver-embedded/src/main/com/mongodb/embedded/client/MongoClients.java
public static synchronized MongoClient create(final MongoClientSettings mongoClientSettings) {
        if (mongoEmbeddedLibrary == null) {
            throw new MongoClientEmbeddedException("The mongo embedded library must be initialized first.");
        }
        try {
            Cluster cluster = new EmbeddedCluster(mongoEmbeddedLibrary, mongoClientSettings);
            return new MongoClientImpl(cluster, mongoClientSettings.getWrappedMongoClientSettings(), null);
        } catch (Exception e) {
            throw new MongoClientEmbeddedException(format("Could not create a new embedded cluster.%n"
                    + "Please ensure any existing MongoClients are fully closed before trying to create a new one.%n"
                    + "Server error message: %s", e.getMessage()), e);
        }
    }
public static synchronized MongoClient create(final MongoClientSettings mongoClientSettings) {
        if (mongoEmbeddedLibrary == null) {
            throw new MongoClientEmbeddedException("The mongo embedded library must be initialized first.");
        }
        try {
            Cluster cluster = new EmbeddedCluster(mongoEmbeddedLibrary, mongoClientSettings);
            return new MongoClientImpl(cluster, mongoClientSettings.getWrappedMongoClientSettings(), null);
        } catch (Exception e) {
            throw new MongoClientEmbeddedException(format("Could not create a new embedded cluster.%n"
                    + "Please ensure any existing MongoClients are fully closed before trying to create a new one.%n"
                    + "Server error message: %s", e.getMessage()), e);
        }
    }
Creates a new client.

@param mongoClientSettings the mongoClientSettings
@return the client