NullPointerException in StaticTypeCheckingVisitor

java.lang.NullPointerException
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.inferReturnTypeGenerics(StaticTypeCheckingVisitor.java:2618)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:1791)
	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:67)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitBinaryExpression(CodeVisitorSupport.java:144)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitBinaryExpression(StaticTypeCheckingVisitor.java:390)
	at org.codehaus.groovy.ast.expr.BinaryExpression.visit(BinaryExpression.java:49)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:69)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:195)
	at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:40)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:35)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:165)
	at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:69)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:101)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:112)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:1179)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:123)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:1403)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.silentlyVisitMethodNode(StaticTypeCheckingVisitor.java:1558)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:1783)
	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:67)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitListOfExpressions(CodeVisitorSupport.java:273)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitTupleExpression(CodeVisitorSupport.java:178)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitArgumentlistExpression(CodeVisitorSupport.java:283)
	at org.codehaus.groovy.ast.expr.ArgumentListExpression.visit(ArgumentListExpression.java:74)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:1610)
	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:67)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitBinaryExpression(CodeVisitorSupport.java:144)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitBinaryExpression(StaticTypeCheckingVisitor.java:390)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitDeclarationExpression(CodeVisitorSupport.java:245)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitDeclarationExpression(ClassCodeVisitorSupport.java:107)
	at org.codehaus.groovy.ast.expr.DeclarationExpression.visit(DeclarationExpression.java:87)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:69)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:195)
	at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:40)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:35)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:165)
	at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:69)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:101)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:112)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:1179)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:123)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:1403)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:1377)
	at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1056)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:50)
	at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:216)
	at org.codehaus.groovy.transform.StaticTypesTransformation.visit(StaticTypesTransformation.java:73)
	at org.codehaus.groovy.transform.ASTTransformationVisitor.visitClass(ASTTransformationVisitor.java:132)
	at org.codehaus.groovy.transform.ASTTransformationVisitor$2.call(ASTTransformationVisitor.java:176)
	at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1024)
	at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:562)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:540)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:517)
	at org.jetbrains.groovy.compiler.rt.GroovyCompilerWrapper.compile(GroovyCompilerWrapper.java:43)
	at org.jetbrains.groovy.compiler.rt.GroovycRunner.main(GroovycRunner.java:150)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:108)