predictCandidatesInternal: Identify candidate internal exons
In ldg21/SGSeq: Splice event prediction and quantification from RNA-seq data

Identify candidate internal exons based on previously identified splice sites and regions with sufficient read coverage.

1	predictCandidatesInternal(islands, splicesites, frag_coverage, relCov)

`islands`	`IRanges` of genomic regions with minimal read coverage required for internal exon prediction
`splicesites`	`IRanges` of splice sites with metadata columns “type” and “N”
`frag_coverage`	`Rle` object with fragment coverage
`relCov`	Minimum relative coverage required for exon prediction