Refactor to add abstract base class for sparse indexed vector types
add getInternalData and getInternalIndex for sparse indexed vector types
indexing overrides
shared dotProduct implementation for sparse indexed vectors
shared isZero and isRangeZero for sparse indexed vectors
Share more sparse indexed code
refa ctoring shared implementations
share addToArray implementation
more refactoring to share sparse indexed implementation
more common code refactoring
more common code refactoring
fixes and refactoring
refactoring
more indexed vector implementation sharing
extra validation of invariant