https://developers.google.com/protocol-buffers/protobuf-java/: Core Protocol Buffers library. Protocol Buffers are a way of encoding structured data in an efficient yet extensible format. 
interface com.google.protobuf.MapFieldSchema
  minor version: 0
  major version: 59
  flags: flags: (0x0600) ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.google.protobuf.MapFieldSchema
  super_class: java.lang.Object
{
  public abstract java.util.Map<?, ?> forMutableMapData();
    descriptor: (Ljava/lang/Object;)Ljava/util/Map;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (Ljava/lang/Object;)Ljava/util/Map<**>;
    MethodParameters:
          Name  Flags
      mapField  

  public abstract java.util.Map<?, ?> forMapData();
    descriptor: (Ljava/lang/Object;)Ljava/util/Map;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (Ljava/lang/Object;)Ljava/util/Map<**>;
    MethodParameters:
          Name  Flags
      mapField  

  public abstract boolean isImmutable(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
          Name  Flags
      mapField  

  public abstract java.lang.Object toImmutable(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
          Name  Flags
      mapField  

  public abstract java.lang.Object newMapField(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
                 Name  Flags
      mapDefaultEntry  

  public abstract com.google.protobuf.MapEntryLite$Metadata<?, ?> forMapMetadata();
    descriptor: (Ljava/lang/Object;)Lcom/google/protobuf/MapEntryLite$Metadata;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (Ljava/lang/Object;)Lcom/google/protobuf/MapEntryLite$Metadata<**>;
    MethodParameters:
                 Name  Flags
      mapDefaultEntry  

  public abstract java.lang.Object mergeFrom(java.lang.Object, java.lang.Object);
    descriptor: (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
              Name  Flags
      destMapField  
      srcMapField   

  public abstract int getSerializedSize(int, java.lang.Object, java.lang.Object);
    descriptor: (ILjava/lang/Object;Ljava/lang/Object;)I
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
                 Name  Flags
      fieldNumber      
      mapField         
      mapDefaultEntry  
}
SourceFile: "MapFieldSchema.java"
InnerClasses:
  Metadata = com.google.protobuf.MapEntryLite$Metadata of com.google.protobuf.MapEntryLite