code: def read_header(fd, endian):
      
      flag_class, nzmax = read_elements(fd, endian, ['miUINT32'])
      header = {
          'mclass': flag_class & 0x0FF,
          'is_logical': (flag_class >> 9 & 1) == 1,
          'is_global': (flag_class >> 10 & 1) == 1,
          'is_complex': (flag_class >> 11 & 1) == 1,
          'nzmax': nzmax
      }
      header['dims'] = read_elements(fd, endian, ['miINT32'])
      header['n_dims'] = len(header['dims'])
      if header['n_dims'] != 2:
          raise ParseError('Only matrices with dimension 2 are supported.')
      header['name'] = read_elements(fd, endian, ['miINT8'], is_name=True)
      return header
docs: Read and return the matrix header.