https://source.android.com/ 
public interface android.widget.SectionIndexer
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: android.widget.SectionIndexer
  super_class: java.lang.Object
{
  public abstract java.lang.Object[] getSections();
    descriptor: ()[Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract int getPositionForSection(int);
    descriptor: (I)I
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
              Name  Flags
      sectionIndex  

  public abstract int getSectionForPosition(int);
    descriptor: (I)I
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
          Name  Flags
      position  
}
SourceFile: "SectionIndexer.java"