class_docstr: This class allows to capture writes to sys.stdout|stderr "in-memory"
  and will raise errors on tries to read from sys.stdin. It only
  modifies sys.stdout|stderr|stdin attributes and does not
  touch underlying File Descriptors (use StdCaptureFD for that).
docstr: return snapshot value of stdout/stderr capturings. 
docstr_tok: ["return","snapshot","value","of","stdout\/stderr","capturings","."]
code: def readouterr(self):
      """return snapshot value of stdout/stderr capturings."""
      out = err = ""
      if self.out:
          out = self.out.getvalue()
          self.out.truncate(0)
          self.out.seek(0)
      if self.err:
          err = self.err.getvalue()
          self.err.truncate(0)
          self.err.seek(0)
      return out, err
  
imports: import os
  import sys
  import py
  import tempfile
label_desc: Use image node_id 5 for calling the StdCapture obj's underlying member method code with example usage: obj.readouterr() and returns: out,  err