add interface (#18)

Author: candiduslynx

lib/build.gradle

@@ -33,6 +33,7 @@ dependencies {
     implementation "io.grpc:grpc-services:1.57.1"
     implementation "io.grpc:grpc-testing:1.57.1"
     implementation "io.cloudquery:plugin-pb-java:0.0.5"
+    implementation "org.apache.arrow:arrow-vector:12.0.1"
 }
 
 testing {

lib/src/main/java/io/cloudquery/scalar/Scalar.java

@@ -0,0 +1,17 @@
+package io.cloudquery.scalar;
+
+import org.apache.arrow.vector.types.pojo.ArrowType;
+
+public interface Scalar {
+    String String();
+
+    Boolean IsValid();
+
+    ArrowType DataType();
+
+    void Set(Object obj);
+
+    Object Get();
+
+    Boolean Equal(Scalar other);
+}