Project: s41467-024-52027-9 | Function: find_sv_opportunities (r)

system: You are an expert R programmer implementing algorithms from scientific papers.
Complete the masked function based on the algorithm description.
Follow R best practices and maintain consistent code style.
Return **only** the complete R function code.

user: Complete this R function:

**DESCRIPTION:** Identifies structural variation opportunities (deletions, duplications, inversions) from repeat pattern matrices by finding combinations of identical segments and determining their orientations

**KEY TERMS:** {
  "sv_opportunities": "structural variation opportunities",
  "combn": "combinations of identical columns",
  "orientation": "relative orientation of segments"
}

**CONTEXT CODE:** #' Find SV opportunities
#'
#' @description Building block: Take in a 'bitlocus',
#' and return a list of NAHR-driven rearrangements that
#' are possible on the reference sequence.
#'
#' @param sample  an nxm matrix (n=gridpoints_x, m=gridpoints_y)
#' @return A dataframe with columns 'p1', 'p2', 'sv'
#'
#' @author Wolfram Hoeps
#' @export
find_sv_opportunities <- function(sample) {
  stop("Function implementation has been masked")
}

Complete the function implementation replacing "stop("Not implemented")".