code: def openblas_threads_text():
      """C header for OpenBLAS threads interface"""
      header = """
      extern "C"
      {
          void openblas_set_num_threads(int);
          void goto_set_num_threads(int);
          int openblas_get_num_threads(void);
      }
      """
      return header
  
file_path: pytensor/pytensor/tensor/blas_headers.py
imports: import logging
  import os
  import sys
  import textwrap
  from os.path import dirname
  from pytensor.configdefaults import config
  from pytensor.link.c.cmodule import GCC_compiler
label_desc: Use image node_id 5 for calling a global function with example usage: openblas_threads_text() and returns: header