private void assertJavaTypesKnown() {
        final Map<String, Class<?>> unmapped = new LinkedHashMap<>();
        
        inner.forEach((key, clazz) -> {
            if (StandardJavaTypeMapping.stream()
                .noneMatch(jtm -> jtm.getJavaClass().equals(clazz))) {
                unmapped.put(key, clazz);
            }
        });
        
        if (!unmapped.isEmpty()) {
            throw new SpeedmentException(
                "There are mappings that have no " + 
                StandardJavaTypeMapping.class.getSimpleName() + 
                " " + unmapped
            );
        }
    }
Sets up the java type map for this database type

@param installer  the installer
@see <a href="http://docs.oracle.com/javase/1.5.0/docs/guide/jdbc/getstart/mapping.html">Official Mappings</a>
runtime-parent/runtime-core/src/main/java/com/speedment/runtime/core/internal/db/JavaTypeMapImpl.java