protected static DistributedSystem getConnection(Properties config) {
    // In an admin VM you can have a connection to more than one
    // distributed system. If we are already connected to the desired
    // distributed system, return that connection.
    for (InternalDistributedSystem existingSystem : existingSystems) {
      if (existingSystem.sameSystemAs(config)) {
        Assert.assertTrue(existingSystem.isConnected());
        return existingSystem;
      }
    }

    return null;
  }
Returns an existing connection to the distributed system described by the given properties.

@param config the properties used when creating a connection to the distributed system
@return a connection to the distributed system that is appropriate for administration

@since GemFire 4.0
geode-core/src/main/java/org/apache/geode/distributed/DistributedSystem.java