virtual const const char *GetType() const
Return the ``bond type name'' string of an bond. This value is
typically used when reading and writing molecular formats. For
example, in Sybyl mol2 file, the bond type name ``am'' means that the
bond should be treated as an amide bond. The default value is the
empty string. The bond type name property may be set using the
OEBondBase::SetType
method.