title: How to check if a field's implements an interface?
body: <p>If I have an <code>org.eclipse.jdt.internal.compiler.ast.FieldDeclaration</code>, how would I check if the type of the field implements an interface, let's say <code>Serializable</code>? I don't see any documentation for <code>org.eclipse.jdt.internal</code>.</p>
  
  <p>I found <a href="https://stackoverflow.com/questions/15800942/extract-interface-that-a-class-implementing-using-ast-parser">extract interface that a class implementing using AST parser</a>, but that one talks about <code>org.eclipse.jdt.core.dom.FieldDeclaration</code>.</p>