public SDVariable firstIndex(String name, SDVariable in, Condition condition, int... dimensions) {
        return firstIndex(name, in, condition, false, dimensions);
    }
public SDVariable firstIndex ( String name , SDVariable in , Condition condition , int ... dimensions ) { return firstIndex ( name , in , condition , false , dimensions ) ; }
First index reduction operation.<br>
Returns a variable that contains the index of the first element that matches the specified condition (for each
slice along the specified dimensions)

@param name       Name of the output variable
@param in         Input variable
@param condition  Condition to check on input variable
@param dimensions Dimensions to reduce over. If dimensions are not specified, full array reduction is performed
@return Reduced array of rank (input rank - num dimensions)