code: public final Node getPropertyNode(String propertyName) {
      Property p = getSlot(propertyName);
      return p == null ? null : p.getNode();
    }
docs: Gets the node corresponding to the definition of the specified property.
  This could be the node corresponding to declaration of the property or the
  node corresponding to the first reference to this property, e.g.,
  "this.propertyName" in a constructor. Note this is mainly intended to be
  an estimate of where in the source code a property is defined. Sometime
  the returned node is not even part of the global AST but in the AST of the
  JsDoc that defines a type.
  
  @param propertyName the name of the property
  @return the {@code Node} corresponding to the property or null.