better error checking in Dock.getConstant(String)

diff --git a/src/edu/berkeley/fleet/api/Dock.java b/src/edu/berkeley/fleet/api/Dock.java
index be4d558..e0b79fe 100644 (file)
--- a/src/edu/berkeley/fleet/api/Dock.java
+++ b/src/edu/berkeley/fleet/api/Dock.java
@@ -41,7 +41,7 @@ public abstract class Dock {
 
     /** get a constant associated with a dock; returns null if none found */
     public BitVector getConstant(String constantName) {
-        return null;
+        throw new RuntimeException("unknown constant \""+constantName+"\" on dock " + this);
     }
 
     public String toString() { return getShip()+"."+getName(); }