code: private static HikariDataSource createPool(String url, String username, String password,
              int minPoolSize, int maxPoolSize, long connectionTimeoutMs) {
  
          HikariDataSource ds = new HikariDataSource();
          ds.setJdbcUrl(url);
          ds.setUsername(username);
          ds.setPassword(password);
          ds.setMinimumIdle(minPoolSize);
          ds.setMaximumPoolSize(maxPoolSize);
          ds.setConnectionTimeout(connectionTimeoutMs);
          return ds;
      }
docs: Returns a new pooled data source based on jdbc url.
  
  @param url
  jdbc url
  @param username
  login username
  @param password
  login password
  @param minPoolSize
  minimum database connection pool size
  @param maxPoolSize
  maximum database connection pool size
  @param connectionTimeoutMs
  @return