findOverlaps on
  two RangesList objects.
queryHits(x): Equivalent to
      unname(as.matrix(x)[,1]).
    subjectHits(x): Equivalent to
      unname(as.matrix(x)[,2]).
    space(x): gets the character vector naming the space
      in the query RangesList for each hit, or NULL
      if the query did not have any names.
    x is a HitsList object. as.matrix(x): calls as.matrix on each
      Hits, combines them row-wise and offsets the
      indices so that they are aligned with the result of calling
      unlist on the query and subject.
    as.table(x): counts the number of hits for each
      query element in x and outputs the counts as a table,
      which is aligned with the result of calling unlist
      on the query.
    t(x): Interchange the query and subject in each space
      of x, returns a transposed HitsList object.as.matrix method coerces a HitsList object in a
  similar way to Hits, except a column is prepended that indicates
  which space (or element in the query RangesList)
  to which the row corresponds.  The as.table method flattens or unlists the list, counts the
  number of hits for each query range and outputs the counts as a
  table, which has the same shape as from a single Hits
  object.
  To transpose a HitsList object x, so that the subject
  and query in each space are interchanged, call t(x). This
  allows, for example, counting the number of hits for each subject
  element using as.table.
findOverlaps in the IRanges package,
          which returns a HitsList object when the query and subject are
          RangesList objects.