You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: extra_nii_hdr.m
    path of file: ./repos/bspm/thirdparty/bramila/external/ISC_toolbox/niftitools
    
    the code of the file until where you have to start completion: %  Decode extra NIFTI header information into hdr.extra
%
%  Usage: hdr = extra_nii_hdr(hdr)
%
%  hdr can be obtained from load_nii_hdr
%
%  NIFTI data format can be found on: http://nifti.nimh.nih.gov
%
%  - Jimmy Shen (jimmy@rotman-baycrest.on.ca)
%
function hdr = extra_nii_hdr(hdr)

   switch hdr.dime.datatype
   case 1
      extra.N
    
function hdr = extra_nii_hdr(hdr)

   switch hdr.dime.datatype
   case 1
      extra.NIFTI_DATATYPES = 'DT_BINARY';
   case 2
      extra.NIFTI_DATATYPES = 'DT_UINT8';
   case 4
      extra.NIFTI_DATATYPES = 'DT_INT16';
   case 8
      extra.NIFTI_DATATYPES = 'DT_INT32';
   case 16
      extra.NIFTI_DATATYPES = 'DT_FLOAT32';
   case 32
      extra.NIFTI_DATATYPES = 'DT_COMPLEX64';
   case 64
      extra.NIFTI_DATATYPES = 'DT_FLOAT64';
   case 128
      extra.NIFTI_DATATYPES = 'DT_RGB24';
   case 256
      extra.NIFTI_DATATYPES = 'DT_INT8';
   case 512
      extra.NIFTI_DATATYPES = 'DT_UINT16';
   case 768
      extra.NIFTI_DATATYPES = 'DT_UINT32';
   case 1024
      extra.NIFTI_DATATYPES = 'DT_INT64';
   case 1280
      extra.NIFTI_DATATYPES = 'DT_UINT64';
   case 1536
      extra.NIFTI_DATATYPES = 'DT_FLOAT128';
   case 1792
      extra.NIFTI_DATATYPES = 'DT_COMPLEX128';
   case 2048
      extra.NIFTI_DATATYPES = 'DT_COMPLEX256';
   otherwise
      extra.NIFTI_DATATYPES = 'DT_UNKNOWN';
   end