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: linearKernel.m
    path of file: ./repos/Coding-Guide/Notes/ml/coursera/machine-learning-ex6/ex6
    
    the code of the file until where you have to start completion: function sim = linearKernel(x1, x2)

    
function sim = linearKernel(x1, x2)
%LINEARKERNEL returns a linear kernel between x1 and x2
%   sim = linearKernel(x1, x2) returns a linear kernel between x1 and x2
%   and returns the value in sim

% Ensure that x1 and x2 are column vectors
x1 = x1(:); x2 = x2(:);

% Compute the kernel
sim = x1' * x2;  % dot product

end