private DozerClassLoader getClassLoader() {
        if (fluentDefinedClassLoader == null) {
            if (RuntimeUtils.isOSGi()) {
                return new OSGiClassLoader(Activator.getBundle().getBundleContext());
            } else {
                return new DefaultClassLoader(DozerBeanMapperBuilder.class.getClassLoader());
            }
        } else {
            return fluentDefinedClassLoader;
        }
    }
Creates an instance of {@link Mapper}. Mapper is configured according to the current builder state.
<p>
Subsequent calls of this method will return new instances.

@return new instance of {@link Mapper}.
core/src/main/java/com/github/dozermapper/core/DozerBeanMapperBuilder.java