separate resource extraction from supported interfaces

Author: zeitlinger

instrumentation/resources/library/src/main/java/io/opentelemetry/instrumentation/resources/AttributeResourceProvider.java

@@ -9,7 +9,6 @@
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
-import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.internal.ConditionalResourceProvider;
 import io.opentelemetry.sdk.resources.Resource;
@@ -21,7 +20,6 @@
 import java.util.Set;
 import java.util.function.Function;
 import java.util.stream.Collectors;
-import javax.annotation.Nullable;
 
 /**
  * An easier alternative to {@link io.opentelemetry.sdk.autoconfigure.spi.ResourceProvider}, which
@@ -67,25 +65,16 @@ public final boolean shouldApply(ConfigProperties config, Resource existing) {
 
   @Override
   public final Resource createResource(ConfigProperties config) {
-    return create(filteredKeys);
-  }
-
-  @SuppressWarnings({"unchecked", "rawtypes"})
-  public final Resource createResource(DeclarativeConfigProperties config) {
-    return create((Set) attributeGetters.keySet());
-  }
-
-  private Resource create(@Nullable Set<AttributeKey<?>> keys) {
-    if (keys == null) {
-      throw new IllegalStateException("shouldApply should be called first");
-    }
     return attributeProvider
         .readData()
         .map(
             data -> {
+              if (filteredKeys == null) {
+                throw new IllegalStateException("shouldApply should be called first");
+              }
               AttributesBuilder builder = Attributes.builder();
               attributeGetters.entrySet().stream()
-                  .filter(e -> keys.contains(e.getKey()))
+                  .filter(e -> filteredKeys.contains(e.getKey()))
                   .forEach(
                       e ->
                           e.getValue()