More cleanups from review.

Author: jsuereth

docs/apidiffs/current_vs_latest/opentelemetry-sdk-common.txt

@@ -1,5 +1,4 @@
 Comparing source compatibility of opentelemetry-sdk-common-1.52.0-SNAPSHOT.jar against opentelemetry-sdk-common-1.51.0.jar
 ***  MODIFIED CLASS: PUBLIC ABSTRACT io.opentelemetry.sdk.resources.Resource  (not serializable)
 	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
-	+++  NEW METHOD: PUBLIC(+) STATIC(+) io.opentelemetry.sdk.resources.Resource create(io.opentelemetry.api.common.Attributes, java.lang.String, java.util.Collection<io.opentelemetry.sdk.resources.internal.Entity>)
 	***  MODIFIED METHOD: PUBLIC NON_ABSTRACT (<- ABSTRACT) io.opentelemetry.api.common.Attributes getAttributes()

sdk/common/src/main/java/io/opentelemetry/sdk/resources/internal/SdkEntityBuilder.java

@@ -22,6 +22,7 @@ final class SdkEntityBuilder implements EntityBuilder {
   @Nullable private String schemaUrl;
 
   SdkEntityBuilder(String entityType) {
+    AttributeCheckUtil.isValid(entityType);
     this.entityType = entityType;
     this.description = Attributes.empty();
     this.id = Attributes.empty();
@@ -42,12 +43,14 @@ public EntityBuilder setSchemaUrl(String schemaUrl) {
 
   @Override
   public EntityBuilder withDescription(Attributes description) {
+    AttributeCheckUtil.checkAttributes(description);
     this.description = description;
     return this;
   }
 
   @Override
   public EntityBuilder withId(Attributes id) {
+    AttributeCheckUtil.checkAttributes(id);
     this.id = id;
     return this;
   }