Add a debug check to sniff out errors like typos

src/main/java/com/gtnewhorizon/structurelib/structure/IStructureDefinition.java

@@ -13,8 +13,11 @@ public interface IStructureDefinition<T> {
 	/**
 	 * Used internally
 	 *
+	 * Might, but is not required, to throw {@link java.util.NoSuchElementException} if the given structure piece is not found.
+	 *
 	 * @param name same name as for other methods here
 	 * @return the array of elements to process
+	 * @throws java.util.NoSuchElementException if the given structure piece is not found and the moon phase perfectly matches
 	 */
 	IStructureElement<T>[] getStructureFor(String name);
 

src/main/java/com/gtnewhorizon/structurelib/structure/StructureDefinition.java

@@ -193,6 +193,9 @@ public class StructureDefinition<T> implements IStructureDefinition<T> {
 
 	@Override
 	public IStructureElement<T>[] getStructureFor(String name) {
-		return structures.get(name);
+		IStructureElement<T>[] elements = structures.get(name);
+		if (elements == null)
+			throw new NoSuchElementException(name);
+		return elements;
 	}
 }