@Override
    public String toString() {

        final StringBuilder builder = new StringBuilder(leftVariable.toString());

        if (!leftSwizzling.isEmpty()) {
            builder.append('.').append(leftSwizzling);
        }

        builder.append(" = ");

        if (rightVariable != null) {

            builder.append(rightVariable.getType())
                    .append(' ')
                    .append(rightVariable.getNameSpace())
                    .append('.')
                    .append(rightVariable.getName());

            if (!rightSwizzling.isEmpty()) {
                builder.append('.').append(rightSwizzling);
            }

        } else if (rightExpression != null) {
            builder.append(rightExpression);
        }

        if (condition != null && !condition.isEmpty()) {
            builder.append(" : ").append(condition);
        }

        return builder.toString();
    }
jme serialization (not used)

@param im the importer
@throws IOException from the importer
jme3-core/src/main/java/com/jme3/shader/VariableMapping.java