Fix build.

Author: khatchad

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/analysis/Util.java

@@ -26,6 +26,7 @@
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.ASTVisitor;
 import org.eclipse.jdt.core.dom.CompilationUnit;
+import org.eclipse.jdt.core.dom.Expression;
 import org.eclipse.jdt.core.dom.ITypeBinding;
 import org.eclipse.jdt.core.dom.MethodInvocation;
 import org.eclipse.jdt.core.dom.SimpleName;