code: def isstr(node):
      return isinstance(node, ast.Constant) and isinstance(
          node.value, str
      )
  
imports: import gast
  from pythran.tables import MODULES
  from pythran.conversion import mangle, demangle
  from functools import reduce
  from contextlib import contextmanager
label_desc: Use image node_id 1 for calling a global function with example usage: isstr(node) and returns: unknown