human
Solve the following python programming problem given the following code:
@ collective 
def _solve(self, A, x, b) : 
    self._set_parameters () 
    if (not (self.getOperators () [0] == A.handle)) : 
        self.setOperators (x.handle) 
        if ((self.parameters ['pc_type'] == 'fieldsplit') and (A.sparsity.shape != (1, 1))) : 
            ises = A.sparsity.toset.field_ises 
            fises = [(str (i), iset) for (i, iset) in enumerate (ises)] 
            self.getPC ().setFieldSplitIS (* fises) 
if self.parameters ['plot_convergence'] : 
        self.reshist = [] 
        def monitor(ksp, its, norm) : 
            self.reshist.append (norm) 
            debug (('%3d KSP Residual norm %14.12e' % (its, norm))) 
self.setMonitor (monitor) 
with timed_region ('PETSc Krylov solver') : 
        with b.vec_ro as bv : 
            with x.vec as xv : 
                PETSc.KSP.solve (self, bv, xv) 
if self.parameters ['plot_convergence'] : 
        self.cancelMonitor () 
        try : 
            import pylab 
            pylab.semilogy (self.reshist) 
            pylab.title ('Convergence history') 
            pylab.xlabel ('Iteration') 
            pylab.ylabel ('Residual norm') 
            pylab.savefig (('%sreshist_%04d.png' % (self.parameters ['plot_prefix'], self._count))) 
except ImportError : 
            warning ('pylab not available, not plotting convergence history.') 
r = self.getConvergedReason () 
    debug (('Converged reason: %s' % self._reasons [r])) 
    debug (('Iterations: %s' % self.getIterationNumber ())) 
    debug (('Residual norm: %s' % self.getResidualNorm ())) 
    if (r < 0) : 
        msg = ('KSP Solver failed to converge in %d iterations: %s (Residual norm: %e)' % (self.getIterationNumber (), self._reasons [r], self.getResidualNorm ())) 
        if self.parameters ['error_on_nonconvergence'] : 
            raise RuntimeError (msg) 
else : 
            warning (msg) 

    
    

    Fix the buggy line: self.setOperators (x.handle)
assistant
#Here is Python code to fix the buggy line: self.

self.setOperators (A.handle)