title: How to get all query parameters from go *gin.context object
body: <p>I am looking at <code>https://godoc.org/github.com/gin-gonic/gin</code> documentation for a method which returns list of all the query parameters passed. There are methods which return value of a query parameter. Is there any method which returns list of all the query parameters passed ? It's ok if we don't get values. I am fetching the values of the query parameter using the following code. But this code can only check if the query parameter exists or not.</p>
  
  <pre><code>func myHandler(c *gin.Context) {
  
      // check for query params
      if queryParam, ok := c.GetQuery("startingIndex"); ok {
          if queryParam == "" {
              c.Header("Content-Type", "application/json")
              c.JSON(http.StatusNotFound,
                  gin.H{"Error: ": "Invalid startingIndex on search filter!"})
              c.Abort()
              return
          }
      }
  }
  </code></pre>