code: def _warn_for_non_extern_non_static_global_variable(decl):
      if not decl.storage:
          import warnings
  
          warnings.warn(
              "Global variable '%s' in cdef(): for consistency "
              "with C it should have a storage class specifier "
              "(usually 'extern')" % (decl.name,)
          )
  
imports: from .None import model
  from .commontypes import COMMON_TYPES, resolve_common_type
  from .error import FFIError, CDefError
  import weakref, re, sys
label_desc: Use image node_id 6 for calling a global function with example usage: _warn_for_non_extern_non_static_global_variable(decl) without return types