When yang-maven-plugin populates YangParser with local modules it acquires ASTSchemaSource representation of each of them. This is needed to ascertain the module identity and also acts as an intermediate step to SchemaContext assembly.

If there is a large number of local models, or if they are large, this can take significant amount of time. Since this process is isolated to a particular file, we can make this parallel by leveraging the common pool – hence text-to-AST will be done in parallel, speeding up wall time.