45,51c45
<   // check if energy source already exists
<   Ptr<EnergySource> source = node->GetObject<EnergySource> ();
<   if (source != NULL)
<     {
<       NS_FATAL_ERROR ("Energy source already installed!");
<     }
<   source = m_basicEnergySource.Create<EnergySource> ();
---
>   Ptr<EnergySource> source = m_basicEnergySource.Create<EnergySource> ();