text: #ifndef ENVIROMENT_H
  #define ENVIROMENT_H
  
  struct env_var_itr;
  typedef struct env_var_itr EnvVarItr;
  
  EnvVarItr *init_env_var_itr(void);
  void free_env_var_itr(EnvVarItr *);
  int env_itr(EnvVarItr *itr, const char **, const char **);
  char *get_env(char *);
  
  #endif
  