Added method for checking whether PDDL description contains problem.

include/plasp/pddl/Description.h

@@ -28,6 +28,8 @@ class Description
 
 	public:
 		const Domain &domain() const;
+
+		bool containsProblem() const;
 		const Problem &problem() const;
 
 	private:

src/plasp/pddl/Description.cpp

@@ -113,6 +113,13 @@ const Domain &Description::domain() const
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+bool Description::containsProblem() const
+{
+	return m_problem.get() != nullptr;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 const Problem &Description::problem() const
 {
 	BOOST_ASSERT(m_problem);