protected void addExecution(final DeployedOperation source, final DeployedOperation target) { final ComposedKey<DeployedOperation, DeployedOperation> key = ComposedKey.of(source, target); if (!this.executionModel.getAggregatedInvocations().containsKey(key)) { final AggregatedInvocation invocation = this.factory.createAggregatedInvocation(); invocation.setSource(source); invocation.setTarget(target); this.executionModel.getAggregatedInvocations().put(key, invocation); } }