code: def _to_field(M):
      """Convert a DomainMatrix to a field if possible."""
      K = M.domain
      if K.has_assoc_Field:
          return M.to_field()
      else:
          return M
  
file_path: sympy/sympy/polys/matrices/rref.py
imports: from sympy.polys.domains import ZZ
  from sympy.polys.matrices.sdm import SDM, sdm_irref, sdm_rref_den
  from sympy.polys.matrices.ddm import DDM
  from sympy.polys.matrices.dense import ddm_irref, ddm_irref_den
label_desc: Use image node_id 16 for calling a global function with example usage: _to_field(M) and returns: M, M