Implement check_type `operator` about jdiff HOT 2 CLOSED

    1. all-same: Check if all content values for the specified element are the same. It can also be used to compare 
                 all content values against another specified element.
           - all-same: flap-count
             checks if all values of node <flap-count> in given Xpath is same or not.

    2. is-equal: Check if the value (integer or string) of the specified element matches a given value.
           - is-equal: admin-status, down
             check if value of node <admin-status> in given Xpath is down or not.  

    3. not-equal: Check if the value (integer or string) of the specified element does not match a given value.
           - not-equal: oper-status, down
             check that value of node <oper-status> should not be equal to down.  

    4. contains: determines if an XML element string value contains the provided test-string value.
           - contains: //package-information/name[1], jbase
           checks if jbase is present in given node or not. 

    5. not-contains: determines if an XML element string value does not contain the provided test-string value.
           - not-contains: //output, sync_alarm
           checks if sync_alarm is present in given node or not.


 - Execute Tests Over Elements with Numeric Values
    1. is-gt: Check if the value of a specified element is greater than a given numeric value.
            - is-gt: cpu-total, 2
              checks value of <cpu-total> should be greater than 2  

    2. is-lt: Check if the value of a specified element is lesser than a given numeric value.
            - is-lt temperature, 55
              checks value of <temperature> is 55 or not.  

    3. in-range: Check if the value of a specified element is in the given numeric range.
            - in-range memory-buffer-utilization, 20, 70 
              check if value of <memory-buffer-utilization> is in range of 20, 70  

    4. not-range: Check if the value of a specified element is outside of a given numeric range.
              - not-range: memory-heap-utilization, 5 , 40
                checks if value of <memory-heap-utilization> is not in range of 5 to 40

 - Execute Tests Over Elements with String Values: 
    1. contains: determines if an XML element string value contains the provided test-string value.
           - contains: //package-information/name[1], jbase
             checks if jbase is present in given node or not.

    2. not-contains: determines if an XML element string value does not contain the provided test-string value.
           - not-contains: //output, sync_alarm
           checks if sync_alarm is present in given node or not.

    3. is-in: Check if the specified element string value is included in a given list of strings.
           - is-in: oper-status, down, up
             check if value of <oper-status> in is list (down, up)  

    4. not-in: Check if the specified element string value is NOT included in a given list of strings.
           - not-in :oper-status, down, up
             check if value of <oper-status> in not in list (down, up)  ```