code: public Variable createVariable(Object projectIdOrPath, String key, String value, Boolean isProtected) throws GitLabApiException {
          return (createVariable(projectIdOrPath, key, value, isProtected, null));
      }
docs: Create a new project variable.
  
  <pre><code>GitLab Endpoint: POST /projects/:id/variables</code></pre>
  
  @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
  @param key the key of a variable; must have no more than 255 characters; only A-Z, a-z, 0-9, and _ are allowed, required
  @param value the value for the variable, required
  @param isProtected whether the variable is protected, optional
  @return a Variable instance with the newly created variable
  @throws GitLabApiException if any exception occurs during execution