title: How to specify a "Arguments" with a space in Robot Framework keyword?
body: <p>I am trying to automate the "gmail" login process.</p>
  
  <p>I have written following keywords. When I run this, first two keywords are running successfully. "Click Signin Button" keyword throws "invalid locator or ID : sign in" error.
  Taken this "sign in" from Inspect Element in "chrome" browser.</p>
  
  <pre><code>*** Keywords ***
  Go to gmail page
      Open Browser    ${HOMEPAGE}     ${BROWSER}
  
  Login Page Should Be Open
      Location Should Be      ${LOGINPAGE}    
  
  Click Signin Button
      Click Button        sign in
  </code></pre>
  
  <p>Could anyone please tell, how to give this "sign in" locator (contains a space).</p>
  
  <p>Thanks,</p>
  
  <p>Kumar</p>