element = ((Identifier) expression).getStaticElement();
if (expression instanceof PrefixedIdentifier) {
highlightedNode = ((PrefixedIdentifier) expression).getIdentifier();
}
} else if (expression instanceof PropertyAccess) {
PropertyAccess propertyAccess = (PropertyAccess) expression;
element = propertyAccess.getPropertyName().getStaticElement();
highlightedNode = propertyAccess.getPropertyName();
}
// check if element is assignable
if (element instanceof PropertyAccessorElement) {
PropertyAccessorElement accessor = (PropertyAccessorElement) element;
element = accessor.getVariable();