+ * At specification time, <code>executionSpec</code> represents the spec of the
+ * parameters accepted by the process, with, among others: type, default value
+ * and, optionally, possible values for each parameter. Thus ExecutionSpec might
+ * be a huge object. Note that when marshalling only a reference to a specific
+ * ExecutionSpec is stored in the XML to optimize performance and avoid
+ * redundancy between various ExecutionFlowDesciptor that might have the same
+ * ExecutionSpec.