Groovy closure to implement matcher in Fest
问题 I am trying to create a closure matcher for Fest with Groovy (2.1.6) like this: def matcherLabel = [ isMatching: { JLabel label -> /* do something */ } ] as GenericTypeMatcher<JLabel> GenericTypeMatcher is an abstract class with one method only to implement (isMatching (T t)) but I get this error: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Error casting map to org.fest.swing.core.GenericTypeMatcher, Reason: null at org.codehaus.groovy.runtime.DefaultGroovyMethods.asType