class_docstr: A symbolic companion matrix of a polynomial.
  
  Examples
  ========
  
  >>> from sympy import Poly, Symbol, symbols
  >>> from sympy.matrices.expressions import CompanionMatrix
  >>> x = Symbol('x')
  >>> c0, c1, c2, c3, c4 = symbols('c0:5')
  >>> p = Poly(c0 + c1*x + c2*x**2 + c3*x**3 + c4*x**4 + x**5, x)
  >>> CompanionMatrix(p)
  CompanionMatrix(Poly(x**5 + c4*x**4 + c3*x**3 + c2*x**2 + c1*x + c0,
  x, domain='ZZ[c0,c1,c2,c3,c4]'))
code: def shape(self):
      poly = self.args[0]
      size = poly.degree()
      return size, size
  
file_path: sympy/sympy/matrices/expressions/companion.py
imports: from sympy.core.singleton import S
  from sympy.core.sympify import _sympify
  from sympy.polys.polytools import Poly
  from .matexpr import MatrixExpr
label_desc: Use image node_id 2 for calling the CompanionMatrix obj's underlying member method code with example usage: obj.shape() and returns: size,  size