anchor.diff:  /// Extension on [Allocator] to provide allocation with [NativeType].
   @Since('2.12')
   extension AllocatorAlloc on Allocator {
  -  /// Allocates `sizeOf<T>() * count` bytes of memory using
  -  /// `allocator.allocate`.
  +  /// Allocates `sizeOf<T>() * count` bytes of memory using [allocate].
  +  ///
  +  /// ```dart
  +  /// // This allocates eight bytes, which is enough space for two Int32's.
  +  /// allocator<Int32>(2);
  +  /// ```
     ///
     /// This extension method must be invoked with a compile-time constant [T].
  +  ///
  +  /// To allocate a specific number of bytes, not just a multiple of
  +  /// `sizeOf<T>()`, use [allocate].
  +  /// To allocate with a non constant [T], use [allocate].
  +  /// Prefer [call] for normal use, and use [allocate] for implementing an
  +  /// [Allocator] in terms of other allocators.
     external Pointer<T> call<T extends NativeType>([int count = 1]);
   }
  
positive.code: 
  part of dart.ffi;
  
  /// Manages memory on the native heap.
  @Since('2.12')
  abstract class Allocator {
    /// This interface is meant to be implemented, not extended or mixed in.
  
negative.code:   ///
    /// If [alignment] is provided, the allocated memory will be at least aligned
    /// to [alignment] bytes.
    ///
    /// To allocate a multiple of `sizeOf<T>()` bytes, call the allocator
    /// directly as a function: `allocator<T>(count)` (see [AllocatorAlloc.call]
    /// for details).
    ///
    /// ```dart
    /// // This allocates two bytes. If you intended two Int32's, this is an
    /// // error.
    /// allocator.allocate<Int32>(2);
    ///
    /// // This allocates eight bytes, which is enough space for two Int32's.
    /// // However, this is not the idiomatic way.
    /// allocator.allocate<Int32>(sizeOf<Int32>() * 2);
    ///
    /// // The idiomatic way to allocate space for two Int32 is to call the
    /// // allocator directly as a function.
    /// allocator<Int32>(2);
    /// ```
    ///
    /// Throws an [ArgumentError] if the number of bytes or alignment cannot be
    /// satisfied.
  