How to use 'havingFilter' in helper list

[avi_24]

Hai friends need some information on how to use helper list in prestashop............. I want to use 'havingFilter' in helper list......As per my understanding  we can use 'havingFilter' to sort the helper list according to a particular value (similar to where clause in select query).  The description in prestashop documanetation says as "['havingFilter'] => {true, false},             // If set to true, the WHERE clause used to filter results will use the $_filterHaving variable (optional, default false)."

 

 

Please help me to find a solution. I have already tried to assign a value(similar to one we assign to where clause) $_filterHaving but shows fatal error.....