public Schema add(Schema schema) {
        if (schema.getName() == null)
            throw new IllegalArgumentException("Schema has no name");
        schemas.add(schema);
        return schema;
    }
Registers the given schema to the application to be built during {@link #build}. A
{@link Schema} object is considered to be "raw" if it has not already been processed. This is the case for most
programmatically constructed schemas used in unit tests.

@param schema the object to import
@throws IllegalArgumentException if the given search object has already been processed
config-model/src/main/java/com/yahoo/schema/ApplicationBuilder.java