public final Attribute parse(
      DirectClassFile cf, int context, int offset, ParseObserver observer) {
    if (cf == null) {
      throw new NullPointerException("cf == null");
    }

    if ((context < 0) || (context >= CTX_COUNT)) {
      throw new IllegalArgumentException("bad context");
    }

    CstString name = null;

    try {
      ByteArray bytes = cf.getBytes();
      ConstantPool pool = cf.getConstantPool();
      int nameIdx = bytes.getUnsignedShort(offset);
      int length = bytes.getInt(offset + 2);

      name = (CstString) pool.get(nameIdx);

      if (observer != null) {
        observer.parsed(bytes, offset, 2, "name: " + name.toHuman());
        observer.parsed(bytes, offset + 2, 4, "length: " + Hex.u4(length));
      }

      return parse0(cf, context, name.getString(), offset + 6, length, observer);
    } catch (ParseException ex) {
      ex.addContext(
          "...while parsing "
              + ((name != null) ? (name.toHuman() + " ") : "")
              + "attribute at offset "
              + Hex.u4(offset));
      throw ex;
    }
  }
Parses and makes an attribute based on the bytes at the indicated position in the given array.
This method figures out the name, and then does all the setup to call on to {@link #parse0},
which does the actual construction.

@param cf {@code non-null;} class file to parse from
@param context context to parse in; one of the {@code CTX_*} constants
@param offset offset into {@code dcf}'s {@code bytes} to start parsing at
@param observer {@code null-ok;} parse observer to report to, if any
@return {@code non-null;} an appropriately-constructed {@link Attribute}
android/android_framework/dex-maker/src/main/java/com/android/dx/cf/direct/AttributeFactory.java