#'Visualizes RNAMagnet output as a signaling network
#'
#'@param rnamagnet An object of class \code{\link{rnamagnet}}, as produced by \code{\link{RNAMagnetSignaling}}
#'@param return Determines object to return; one of "summary" or "rnamagnet-class"
#'@param score One of \code{specificity} or \code{volume}, see detail below.
#'@param threshold Threshold interaction strength for including an edge in the network.
#'@param colors A named vector of colors to be used for plotting; names correspond to levels of \code{rnamagnet@class}
#'@param useLabels Plot the population labels on the graph?
#'@param ... Parameters passed to \code{\link[igraph]{plot.igraph}}, e.g. a layout can be stored as described in the example code below
#'@details If \code{score} is set to \code{specificity}, two cell types are connected if they are enriched for interactions.
#'@details If \code{score} is set to \code{volume}, two cell types are connected if there are many interactions between them.
#'@details To understand the difference, consider the following example of three cell types A, B, and C, where A expresses 50 different cytokines to which both B and C express cognate receptors. B expresses 10 cytokines, for which only C expresses cognate receptors. If plotting the number of interactions, A would be connected to B and C; if plotting their specificity, B would be connected to C.