public interface io.reactivex.SingleOperator<Downstream, Upstream>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.reactivex.SingleOperator
  super_class: java.lang.Object
{
  public abstract io.reactivex.SingleObserver<? super Upstream> apply(io.reactivex.SingleObserver<? super Downstream>);
    descriptor: (Lio/reactivex/SingleObserver;)Lio/reactivex/SingleObserver;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Exceptions:
      throws java.lang.Exception
    Signature: (Lio/reactivex/SingleObserver<-TDownstream;>;)Lio/reactivex/SingleObserver<-TUpstream;>;
    RuntimeInvisibleAnnotations: 
      io.reactivex.annotations.NonNull()
    RuntimeInvisibleParameterAnnotations: 
      0:
        io.reactivex.annotations.NonNull()
    MethodParameters:
          Name  Flags
      observer  
}
Signature: <Downstream:Ljava/lang/Object;Upstream:Ljava/lang/Object;>Ljava/lang/Object;
SourceFile: "SingleOperator.java"