= R"DOC(
Pulls in slices of the input tensor, groups them into segments and applies
'{op}' to each segment. Segments need to be sorted and contiguous. See also
SparseUnsortedSegment{op} that doesn't have this requirement.
This op is basically Gather and SortedSegment{op} fused together.
INDICES should contain integers in range 0..N-1 where N is the first dimension
of DATA. INDICES represent which slices of DATA need to be pulled in.
SEGMENT_IDS is a vector that maps each referenced slice of the DATA to a
particular group (segment). Values belonging to the same segment are aggregated
together. SEGMENT_IDS should have the same dimension as INDICES.
The first dimension of the output is equal to the number of input segments,
i.e. `SEGMENT_IDS[-1]+1`. Other dimensions are inherited from the input tensor.
{op_doc}
)DOC"