add task for chunked-scatter

chunked-scatter.wdl

+version 1.0
+
+task ChunkedScatter {
+    input {
+        File inputFile
+        String prefix = "./scatter"
+        Int? chunkSize
+        Int? overlap
+        Int? minimumBasesPerFile
+
+        String dockerImage = "alpine:latest" #TODO
+    }
+
+    command {
+        set -e
+        mkdir -p ~{prefix}
+        chunked-scatter \
+        -p ~{prefix} \
+        -i ~{inputFile} \
+        ~{"-c " + chunkSize} \
+        ~{"-o " + overlap} \
+        ~{"-m " + minimumBasesPerFile}
+    }
+
+    output {
+        Array[File] scatters = glob(prefix + "_*.bed")
+    }
+
+    runtime {
+        memory: 4
+        docker: dockerImage
+    }
+}
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