Inserting into embedded list of orient db through java

This is the sql script that I have used to create the necessary classes :

CREATE CLASS ProductSummary;
CREATE PROPERTY ProductSummary.name STRING (NOTNULL, MANDATORY TRUE);
CREATE PROPERTY ProductSummary.modelNumber LONG (NOTNULL, MANDATORY TRUE);
ALTER CLASS ProductSummary STRICTMODE TRUE;
 
CREATE CLASS PricingSummary;
CREATE PROPERTY PricingSummary.price LONG (NOTNULL, MANDATORY TRUE);
CREATE PROPERTY PricingSummary.discount LONG (NOTNULL, MANDATORY TRUE);
ALTER CLASS PricingSummary STRICTMODE TRUE;
 
CREATE CLASS TotalSummary EXTENDS V;
CREATE PROPERTY TotalSummary.projectLink LINK Project (NOTNULL, MANDATORY TRUE);
CREATE PROPERTY TotalSummary.productSummaries EMBEDDEDLIST ProductSummary;
CREATE PROPERTY TotalSummary.pricingSummaries EMBEDDEDLIST PricingSummary;
ALTER CLASS TotalSummary STRICTMODE TRUE;
CREATE INDEX TotalSummary_projectLink_idx ON TotalSummary (projectLink) UNIQUE;

I am trying to insert some values into my TotalSummary class, where I also need to insert some values into the EmbeddedList for pricingSummaries and productSummaries.

public TotalSummary create(final TotalSummary totalSummary) {
		final Long projectId = 1;
		final StatementBuilder builder = new StatementBuilder();
		final StringBuilder query = new StringBuilder();
		
		final List<Map<?, ?>> productSummaries = totalSummary.getProductSummaries().stream()
				.map(ProductSummary::toMap)
				.collect(Collectors.toList());
		
		final List<Map<?, ?>> pricingSummaries = totalSummary.getPricingSummaries().stream()
				.map(PricingSummary::toMap)
				.collect(Collectors.toList());
		
		
		builder.addAttribute("projectLink = (SELECT FROM project WHERE id = ?)", projectId);
		if ( ! productSummaries.isEmpty()) {
			builder.addAttribute("productSummaries = ?", productSummaries);
		}
		if ( ! pricingSummaries.isEmpty()) {
			builder.addAttribute("pricingSummaries = ?", pricingSummaries);
		}
		
		try {
			insert(TotalSummary.class.getSimpleName(), builder.attributes(), statement -> {
				builder.init(statement);
				return statement;
			});
		} catch (final UncategorizedSQLException e) {
			throw new ConstraintViolationException(totalSummary, ExceptionUtils.getRootCauseMessage(e), e);
		}

		return assertNotNull(findById(projectId));
	}

This is the utility method that I am using to build the insert query : 
protected String insert(final String vertex, final String fieldValuePairs, final PreparedStatementInitializer initializer) {
	final String sql = "INSERT INTO " + vertex + " SET " + fieldValuePairs + " RETURN @rid";
	return executeStatement(sql, initializer);
}

The toMap methods to convert the List<ProductSummary> to List<Map<?,?>>

**ProductSummary**	
public Map<String, Object> toMap() {
	final Map<String, Object> ret = new HashMap<>();
	ret.put("name", name);
	ret.put("model number", Long.valueOf(modelNumber));
	return ret;
}

The toMap methods to convert the List<PricingSummary> to List<Map<?,?>>
**PricingSummary**
public Map<String, Object> toMap() {
	final Map<String, Object> ret = new HashMap<>();
	ret.put("price", Long.valueOf(price));
	ret.put("discount", Long.valueOf(discount));
	return ret;
}

I am getting the following exception when I execute the code

Constraint violation for: TotalSummary@58f79eeb[recordId=<null>,customProperties=[]]. Reason: OValidationException: The field 'TotalSummary.productSummaries' has been declared as EMBEDDEDLIST but an incompatible type is used. 

Things that I have already tried :

1. I have tried to covert to list to json format before adding it to
   the builder like so new Gson().toJson(pricingSummaries);
2. Converted the pricingSummaries and productSummaries toArray().

You defined the summaries as EMBEDDEDLIST ProductSummary but you are passing lists of maps as values.

Try to create real ProductSummary objects instead eg.

OElement ret = db.newEmbeddedElement("ProductSummary");
ret.setProperty("price", Long.valueOf(price));
ret.setProperty("discount", Long.valueOf(discount));