The realization space is
  [1   1   0   0               x1 - x2               x1 - x2   0            1            1                                          x1 - x2    1]
  [0   1   1   1   x1^2 - 2*x1*x2 + x2   x1^2 - 2*x1*x2 + x1   0            0            1                              x1^2 - 2*x1*x2 + x2   x1]
  [0   1   1   0                     0               x1 - x2   1   -x1 + 2*x2   -x1 + 2*x2   -x1^3 + 4*x1^2*x2 - 4*x1*x2^2 - x1*x2 + 2*x2^2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x1^2 - 2*x1*x2 + x2, x1 - 1, x1^3 - 4*x1^2*x2 + 4*x1*x2^2 + 2*x1*x2 - 4*x2^2 + x2, x2, x1^3 - 4*x1^2*x2 + 4*x1*x2^2 + x1*x2 - 3*x2^2 + x2, x1^3 - 4*x1^2*x2 + 4*x1*x2^2 + 2*x1*x2 - 3*x2^2, x1 - 2*x2, x1^4 - 4*x1^3*x2 + 4*x1^2*x2^2 + x1^2*x2 - 2*x1*x2^2 + x1*x2 - x2^2, x2 - 1, x1 - 2*x2 + 1, x1 - x2, x1, x1^3 - 4*x1^2*x2 + x1^2 + 4*x1*x2^2 - 2*x1*x2 + x1 - x2, 2*x1^3 - 8*x1^2*x2 + 8*x1*x2^2 + 3*x1*x2 - 6*x2^2 + x2, x1^3 - 4*x1^2*x2 + 4*x1*x2^2 + x1*x2 + x1 - 2*x2^2 - x2]