def METHOD_NAME(self):
    # The Sun Raster file header is 32 bytes in length
    # and has the following format:
    #     typedef struct _SunRaster
    #     {
    #         DWORD MagicNumber;      /* Magic (identification) number */
    #         DWORD Width;            /* Width of image in pixels */
    #         DWORD Height;           /* Height of image in pixels */
    #         DWORD Depth;            /* Number of bits per pixel */
    #         DWORD Length;           /* Size of image data in bytes */
    #         DWORD Type;             /* Type of raster file */
    #         DWORD ColorMapType;     /* Type of color map */
    #         DWORD ColorMapLength;   /* Size of the color map in bytes */
    #     } SUNRASTER;
    # HEAD
    s = self.fp.read(32)
    if not _accept(s):
        msg = "not an SUN raster file"
        raise SyntaxError(msg)
    offset = 32
    self._size = i32(s, 4), i32(s, 8)
    depth = i32(s, 12)
    # data_length = i32(s, 16)   # unreliable, ignore.
    file_type = i32(s, 20)
    palette_type = i32(s, 24)  # 0: None, 1: RGB, 2: Raw/arbitrary
    palette_length = i32(s, 28)
    if depth == 1:
        self.mode, rawmode = "1", "1;I"
    elif depth == 4:
        self.mode, rawmode = "L", "L;4"
    elif depth == 8:
        self.mode = rawmode = "L"
    elif depth == 24:
        if file_type == 3:
            self.mode, rawmode = "RGB", "RGB"
        else:
            self.mode, rawmode = "RGB", "BGR"
    elif depth == 32:
        if file_type == 3:
            self.mode, rawmode = "RGB", "RGBX"
        else:
            self.mode, rawmode = "RGB", "BGRX"
    else:
        msg = "Unsupported Mode/Bit Depth"
        raise SyntaxError(msg)
    if palette_length:
        if palette_length > 1024:
            msg = "Unsupported Color Palette Length"
            raise SyntaxError(msg)
        if palette_type != 1:
            msg = "Unsupported Palette Type"
            raise SyntaxError(msg)
        offset = offset + palette_length
        self.palette = ImagePalette.raw("RGB;L", self.fp.read(palette_length))
        if self.mode == "L":
            self.mode = "P"
            rawmode = rawmode.replace("L", "P")
    # 16 bit boundaries on stride
    stride = ((self.size[0] * depth + 15) // 16) * 2
    # file type: Type is the version (or flavor) of the bitmap
    # file. The following values are typically found in the Type
    # field:
    # 0000h Old
    # 0001h Standard
    # 0002h Byte-encoded
    # 0003h RGB format
    # 0004h TIFF format
    # 0005h IFF format
    # FFFFh Experimental
    # Old and standard are the same, except for the length tag.
    # byte-encoded is run-length-encoded
    # RGB looks similar to standard, but RGB byte order
    # TIFF and IFF mean that they were converted from T/IFF
    # Experimental means that it's something else.
    # (https://www.fileformat.info/format/sunraster/egff.htm)
    if file_type in (0, 1, 3, 4, 5):
        self.tile = [("raw", (0, 0) + self.size, offset, (rawmode, stride))]
    elif file_type == 2:
        self.tile = [("sun_rle", (0, 0) + self.size, offset, rawmode)]
    else:
        msg = "Unsupported Sun Raster file type"
        raise SyntaxError(msg)