protected static Set<String> getDependencies(ModuleElement ast) {
	return ast.getChildren()
		.stream()
		.filter(me -> me instanceof ExecutableBlock)
		.map(eb -> (ExecutableBlock<?>) eb)
		.filter(EvlGraph::isDependencyWord)
		.map(eb -> eb.getChildren()
				.stream()
				.filter(bc -> bc instanceof OperationCallExpression)
				.map(oce -> (OperationCallExpression) oce)
				.filter(bc -> bc.getOperationName().equals("satisfies"))
				.collect(Collectors.toList()))
		.flatMap(List::stream)
		.map(OperationCallExpression::getParameterExpressions)
		.flatMap(List::stream)
		.map(expr -> (StringLiteral) expr)
		.map(StringLiteral::getValue)
		.collect(Collectors.toSet());
}

    //Stream<Expression> satisfiesParams
    .map(expr -> {
	if (expr instanceof StringLiteral)
             return ((StringLiteral) expr).getValue();
	if (expr instanceof NameExpression)
            return ((NameExpression) expr).getName();
        return expr.execute(context);
    })