title: How to expect some (but not all) arguments with RSpec should_receive?
body: <pre><code>class Foo
    def bar(a, b)
    ...
  
  Foo.should_receive( :bar )
  </code></pre>
  
  <p>expects bar to be called with any arguments.</p>
  
  <pre><code>Foo.should_receive( :bar ).with( :baz, :qux )
  </code></pre>
  
  <p>expects :baz and :qux to be passed in as the params.</p>
  
  <p>How to expect the first param to equal :baz, and not care about the other params?</p>