class AliRsnMother: public TObject

 Copy constructor.
 Does not duplicate pointers.

 Assignment operator.
 Does not duplicate pointers.

 Desctructor.
 Does nothing, since pointers are not created in this class.

 Resets the mother, zeroing all data members.

 If MC info is available, checks if the two tracks in the pair have the same mother.
 If the mother label is the same, the function returns the PDG code of mother,
 otherwise it returns 0.
 The two arguments passed by reference contain the GEANT labels of the mother
 of the two particles to which the two daughters point. This is for being able
 to check if they are really coming from a resonance (indexes >= 0) or not.

 Compute the angle betwee this and the leading particls
 of the reference event (if this was set properly).
 In case one of the two daughters is the leading, return
 a meaningless value, in order to skip this pair.
 if second argument is kTRUE, use MC values.

 Sets the masses for the 4-momenta of the daughters and then
 sums them, taking into account that the space part is set to
 each of them when the reference object is set (see AliRsnDaughter::SetRef)

 Computes the cosine of theta*, which is the angle of one of the daughters
 with respect to the total momentum of the resonance, in its rest frame.
 The arguments are needed to choose which of the daughters one want to use
 and if reconstructed or MC momentum must be used.
 [Contribution from Z. Feckova]

 returns product of DCA of the two daughters

 Print some info of the pair.
 The options are passed to the AliRsnDaughter::Print() method

 Checks that the pair is well initialized:
 - both daughters are good pointers
 - if MC is required, both daughters have a MC reference

 getters

 checks

 angles