netcdf test_struct_nested3 {
  types:
    compound s1_t {
      int field1 ;
    }; // s1_t
    compound s2_t {
      s1_t field2 ;
    }; // s2_t
    compound s3_t {
      s2_t field3 ;
    }; // s2_t
variables:
  s3_t x;
data:
 x = {{{17}}} ;
}