4. The method according to claim 3 , wherein generating the second metamodel comprises: determining whether a node element of the first metamodel is associated with a complex type; if the node element of the first metamodel is not associated with a complex type, generating an attribute of the second metamodel representing the node element of the first metamodel; and if the node element of the first metamodel is associated with a complex type, generating a reference and a second class of the second metamodel representing the node element, where the second class represents the complex data type.
5. The method according to claim 4 , wherein generating the second metamodel comprises: generating, for each association of the first metamodel, a respective reference of the second metamodel.