Error in exercise

package com.teamtreehouse.builder;

public class Connection {
  private String jdbcVendor;
  private String dbName;
  private String username;
  private String password;

  public Connection(String jdbcVendor, String dbName, String username, String password) {
    this.jdbcVendor = jdbcVendor;
    this.dbName = dbName;
    this.username = username;
    this.password = password;
  }

  public Connection(ConnectionBuilder builder) {
    this.jdbcVendor = builder.jdbcVendor;
    this.dbName = builder.dbName;
    this.username = builder.username;
    this.password = builder.password;
  }

  public static class ConnectionBuilder{
    private String jdbcVendor;
    private String dbName;
    private String username;
    private String password;

    public ConnectionBuilder(){}

    public ConnectionBuilder withJdbcVendor(String jdbcVendor) {
      this.jdbcVendor = jdbcVendor;
      return this;
    }

    public ConnectionBuilder withDb(String dbName) {
      this.dbName = dbName;
      return this;
    }

    public ConnectionBuilder withUser(String username, String password) {
      this.username = username;
      this.password = password;
      return this;
    }

    public Connection build() {
      return new Connection(this);
    }
  }
}

import com.teamtreehouse.builder.Connection;
import com.teamtreehouse.builder.Connection.ConnectionBuilder;

public class Application {
  public static void main(String[] args) {
    // TODO: User the builder here instead
    Connection c = new Connection.ConnectionBuilder()
      .withJdbcVendor("sqlite")
      .withDb("languages")
      .withUser("th_user","mysuperlongpassword")
      .build();
  }
}