C++: private _read() method created but never called or accessible in --debug mode
Version: kaitai-struct-compiler 0.8 Universal
KSY file content:
```yaml
meta:
   ks-version: 0.8
   id: myformat
seq:
   -
      id: testval
      type: u4le

```

Generated .h file:
```cpp
#ifndef MYFORMAT_H_
#define MYFORMAT_H_

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

#include "kaitai/kaitaistruct.h"

#include <stdint.h>

#if KAITAI_STRUCT_VERSION < 7000L
#error "Incompatible Kaitai Struct C++/STL API: version 0.7 or later is required"
#endif

class myformat_t : public kaitai::kstruct {

public:

    myformat_t(kaitai::kstream* p__io, kaitai::kstruct* p__parent = 0, myformat_t* p__root = 0);

private:
    void _read();

public:
    ~myformat_t();

private:
    uint32_t m_testval;
    myformat_t* m__root;
    kaitai::kstruct* m__parent;

public:
    uint32_t testval() const { return m_testval; }
    myformat_t* _root() const { return m__root; }
    kaitai::kstruct* _parent() const { return m__parent; }
};

#endif  // MYFORMAT_H_
```

Generated .cpp file content:
```cpp
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

#include "myformat.h"

myformat_t::myformat_t(kaitai::kstream* p__io, kaitai::kstruct* p__parent, myformat_t* p__root) : kaitai::kstruct(p__io) {
    m__parent = p__parent;
    m__root = this;
}

void myformat_t::_read() {
    m_testval = m__io->read_u4le();
}

myformat_t::~myformat_t() {
}
```

The _read() method cannot be called from instances of the class of derived classes.