“…Input References AST Nguyen et al 83 PDG Previous studies 83,85 XMI Previous studies 158,181 Code Previous studies 60,61,122,142,174 Design Previous studies 49,56,82,86,93,97,99,124,130,136,141,160,168,169,186 Software metrics Fourati et al 115 Abbreviations: AST, abstract syntax tree; PDG, program dependency graph; XMI, XML metadata interchange; XML, extended markup language. Figure 13 shows the chronological distributions of the PSs with respect to Java, C, C++, and other programing languages.…”