You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: K_symmetrised.m
    path of file: ./repos/mtex/SO3Fun/SO3KernelFunctions/@SO3Kernel
    
    the code of the file until where you have to start completion: function w = K_symmetrised(psi,q1,q2,CS,SS,varargin)
% evaluate kernel modulo symmetries
%
% Input
%  psi    - @SO3Kernel
%  q1, q2 - @quaternion(s)
%  CS, SS - crystal , specimen @symmetry
%
% Options
%  exact - 
%  epsilon - 
%

    
function w = K_symmetrised(psi,q1,q2,CS,SS,varargin)
% evaluate kernel modulo symmetries
%
% Input
%  psi    - @SO3Kernel
%  q1, q2 - @quaternion(s)
%  CS, SS - crystal , specimen @symmetry
%
% Options
%  exact - 
%  epsilon - 
%
% Description
% K(q1,q2) = Sum(S) Sum(l) A_l Tr T_l(s1^-1 q1 s2)

% only the pur rotational part is of interest 
% TODO
qCS = unique(quaternion(CS));
qSS = unique(quaternion(SS));

if check_option(varargin,'exact')
  epsilon = pi;
else 
  epsilon = min(pi,get_option(varargin,'epsilon',psi.halfwidth*3.5));
end